The research significance of this topic (the process of selecting the topic, the feasibility of discussion and the theoretical and practical research significance of this topic) (1) The process of selecting the topic is in the economic environment of price changes, and the disadvantages of the straight-line depreciation method are gradually emerging with the rapid development of science and technology and the continuous improvement of labor productivity. In order to operate better, according to the requirements of the principle of matching method, the depreciation of fixed assets should be increased at the initial stage and decreased at the later stage of use, which is conducive to a decreasing trend. Pay attention to the depreciation of fixed assets, make enterprises adopt accelerated depreciation method as much as possible, and reduce the enterprise income tax payable. (II) Possibility of discussion This paper provides intellectual and intellectual support for the completion of this topic with the study and accumulation of relevant system knowledge and professional knowledge in the past and the guidance of teachers with relatively reasonable quality. Accelerated depreciation method, also known as decreasing depreciation method, refers to the depreciation expense accrued in each period of fixed assets, which is more accrued in the early stage of use and less in the later stage. Therefore, the depreciation rate of fixed assets is relatively accelerated, and the cost of fixed assets is quickly compensated. Accelerated depreciation method plays a certain role in increasing investment in fixed assets and accelerating technological transformation. In order to encourage the adoption of new technologies, the state allows some enterprises to adopt accelerated depreciation method. (III) Theoretical and practical research significance of the selected topic Changes in fixed assets of enterprises can also bring benefits to enterprises, but the premise is to look at the current actual situation of enterprises in China. Choosing a reasonable depreciation method can promote the development of enterprises. At present, accelerated depreciation method is the fastest compensation method to compensate the cost of fixed assets in the expected service life of enterprises. Because depreciation expense is an integral part of enterprise cost, increasing depreciation expense in each period can promote the renewal of enterprise fixed assets faster, and the choice of depreciation method of fixed assets also directly affects tax planning, the formation of after-tax net profit and the vital interests of enterprises. The calculation and extraction of depreciation will inevitably affect the cost, and then affect the profit level of enterprises, and ultimately affect the weight of corporate tax burden. Because there are differences in depreciation methods, it is possible for enterprises to carry out tax planning. Obviously, it is the key for an enterprise to choose a good depreciation method according to its own actual situation, so as to make it cautious and dynamic, and constantly improve its benefits and social benefits.