Abstract: After a long struggle, mankind has made brilliant achievements in transforming nature and developing social economy. At the same time, ecological destruction and environmental pollution have posed a real threat to human survival and development. Protecting and improving the ecological environment and realizing the sustainable development of human society are urgent and arduous tasks facing all mankind. Therefore, environmental protection and sustainable development are two-in-one and two-in-one tasks. Protecting the environment is the premise of realizing sustainable development. Only by realizing sustainable development can the ecological environment be effectively protected. Protecting the ecological environment and ensuring the harmony between man and nature are the premise of further economic development and the guarantee of the continuation of human civilization. Keywords: environmental protection; Sustainable development; Harmonious development 1 the essence of sustainable development is that sustainable development not only meets the needs of contemporary people, but also does not damage the ability of future generations to meet needs. Sustainable development contains two important connotations: first, need, that is, to meet the basic needs of human beings and improve the quality of life, with special priority given to basic needs; The second is restriction, that is, human development and demand are limited by the carrying capacity of the earth's resources. Development is coordinated and restricted through human technological progress and management activities, and the ability of the environment to meet immediate and future needs is restricted to adapt to the natural environmental capacity. Development without restrictions is unsustainable. Ecological sustainable development is the guarantee of sustainable development, economic sustainable development is the means of sustainable development, and social sustainable development is the ultimate goal of sustainable development. With the emergence of environmental problems, it is urgent to advocate the sustainable development model. Nowadays, the world is facing a series of major problems in population, resources, environment and development. The concept of sustainable development is put forward on the basis of human's deep understanding of the sustainable ability of environment and resources. Sustainable development is to apply the universal laws of material immortality and energy conservation in nature to human beings and natural environment systems as an organic whole. Meeting human needs is the center of social development. On the basis of minimizing resource consumption, human beings are required to improve the utilization rate of resources, achieve more output with less input, promote the growth of renewable resources, and make the conversion rate of material energy achieve the best effect under the condition of mutual coordination within the system to meet people's needs. At the same time, people are required to use it as much as possible while consuming, so as to reduce the natural load and keep the system structure and function in good condition, which has become a new sustainable development model in harmony with human beings and the natural environment. 2 Environmental functions and environmental problems The development of human society is inseparable from the surrounding environment. Environment is often one of the necessary conditions for social development. The promotion or delay of environment to social development reflects the continuous improvement of productivity and the continuous development of natural resources, and the relationship between society and its surrounding environment is deepening day by day. Environment is the foundation of human survival and development. It is also the object of development and utilization. Its main function is to (1) provide all kinds of natural conditions and resources necessary for human activities. Environment is the source of material and energy for human production, and it is also the basic and important condition for the survival of all kinds of creatures. Humans mine coal, oil, natural gas, etc. Starting from the natural geographical environment, we use land resources to produce grain, thus producing a series of economic activities. Therefore, the quantity and quality of environmental resources determine the scale and speed of economic activities. When the speed of human demand for resources exceeds the capacity of natural supply, it is difficult to maintain and sustain development. (2) Consume and assimilate the products produced by human activities, and at the same time, some by-products that are not used for a while will be discharged into the environment and become waste. However, human metabolism and consumption activities also produce various wastes and return them to the surrounding natural environment. When the waste discharge exceeds the self-purification capacity of the environment, the environmental quality will decline. (3) To satisfy the spiritual enjoyment of human existence. Environment can not only provide material resources for human beings, but also meet people's requirements for comfort. Clean air and water are the basic elements of agricultural production and the needs of people's healthy and happy life. Beautiful and comfortable environment makes people feel relaxed and happy, which is conducive to improving the quality of human body and promoting the sustainable development of social economy more effectively. The purpose of environmental protection is to promote the sustainable development of social economy. Faced with many environmental problems, we must strengthen environmental protection. Environmental problems refer to any changes in environmental structure and state that are not conducive to human survival and development. The reasons are both man-made and natural. Its essence is the contradiction between human unreasonable social and economic activities and environmental sustainable development. Environmental problems have become one of the severe challenges facing mankind. It mainly includes primary environmental problems and secondary environmental problems. (1) The primary environmental problem is called the first environmental problem, which is caused by the change of the natural environment itself, with little or no human factors involved. This kind of environmental problem is naturally induced. Only after a long period of natural accumulation, or mainly under the control of natural forces, people lose their control ability and cause certain damage to human society. These environmental problems include earthquakes, volcanic activities, landslides, mudslides, typhoons, floods and droughts. Faced with these problems, we can prevent and reduce the damage during the day. (2) Secondary environmental problems are environmental problems caused by human activities acting on the surrounding environment, also known as secondary environmental problems. It is mainly the problem of environmental decline caused by unreasonable utilization of resources by human beings and the problem of environmental pollution caused by industrial development. . Environmental protection and sustainable development. No matter from the global scope or from the actual situation in China, human civilization has developed to the stage of protecting the ecological environment. Ensuring the harmony between man and nature is the premise of further economic development and the guarantee of the continuation of human civilization. Achieve the goals of environmental protection and sustainable development. We need to do a lot of things. We should adjust the relationship between man and nature, between contemporary people and future generations, and between contemporary people and contemporary people. To truly solve environmental problems, we must first change the current development mode and road of mankind. Development cannot be limited to economic development, and social and economic development and environmental protection cannot be separated, let alone opposed. Development should be the coordinated development of society, economy, population, resources and environment and the all-round development of human beings. On a global scale, the ecological environment has been destroyed and the environmental pollution has become more serious. Only by breaking through the narrow concept of environment, closely linking population, resources, environment and development, and coordinating the relationship between man and environment, development and environment, can environmental problems be solved as a whole. Whether contemporary people can fairly distribute the costs and benefits of environmental protection and establish a set of institutional arrangements to encourage people's environmental protection behavior directly determines the realization of the goal of harmonious coexistence between man and nature; If contemporary people can't achieve some minimum justice, then we can hardly expect them to really care about the interests of distant future generations. Therefore, contemporary collective efforts and everyone's choice are the key to achieving the goal of sustainable development. This is because people's basic needs are met, which is the basic right that people enjoy as human beings. Poverty is the deprivation of this right, which makes the value of human behavior not realized. At the same time, poverty and environmental damage are often mutually causal. Therefore, eliminating poverty and narrowing the gap between the rich and the poor are the inherent requirements for achieving intra-generational equality and the basis for achieving sustainable development. To sum up, in order to achieve the goal of coordinated and sustainable development between human beings and the natural environment, we must protect the environment. Reference [1] Liu Nanwei. Physical geography [M]. Beijing: Science Press, 200 1:548. [2] Li Chunhua. Principles of environmental science [M]. Nanjing: Nanjing University Press, 2003, (4). [3] Hu Wen. Introduction to sustainable development.