Four electricity and four postal services refer to the four major electronic information universities and four major postal universities under the China Electronics Technology Group. These eight universities occupy an important position in China's higher education, have trained a large number of talents in the fields of electronic information, postal communication and so on, and have made important contributions to the development of China's science and technology.

First of all, the four major power stations refer to University of Electronic Science and Technology of China, xidian university, Beijing University of Electronic Technology and Nanjing University of Information Science & Technology. University of Electronic Science and Technology of China, located in Chengdu, Sichuan Province, was founded in 1956. It is one of the earliest electronic and information universities in China, with several national scientific research platforms and laboratories such as the State Key Laboratory of Information and Communication Engineering. Xidian university, located in Xi City, Shaanxi Province, was founded in 1958. It is also one of the earliest electronic information universities in China, with several national scientific research platforms and laboratories such as the State Key Laboratory of Antenna and Microwave Technology. Beijing Dianzi University, located in Beijing, was founded in 1958. It is one of the earliest electronic information universities in China, with several national scientific research platforms and laboratories such as the State Key Laboratory of Communication and Information System. Nanjing University of Information Science & Technology, located in Nanjing, Jiangsu Province, was founded in 1978. It is also one of the earliest electronic information universities in China, with several national scientific research platforms and laboratories such as the State Key Laboratory of Meteorological Satellite Data Processing and Application.

Secondly, the four major postal services refer to China University of Posts and Telecommunications, Nanjing University of Posts and Telecommunications, Chongqing University of Posts and Telecommunications and Xi University of Posts and Telecommunications. China Post College, located in Nanjing, Jiangsu Province, was founded on 1950. It is one of the earliest postal colleges in China and has trained a large number of postal communication talents. Nanjing University of Posts and Telecommunications, located in Nanjing, Jiangsu Province, was founded in 1942. As one of the earliest postal universities in China, it has trained a large number of postal communication talents. Chongqing University of Posts and Telecommunications, located in Chongqing, was founded in 1950. It is also one of the earliest postal universities in China, with several national scientific research platforms and laboratories such as the Key Laboratory of Postal Automation Control of the Ministry of Information Industry. Xi University of Posts and Telecommunications, located in Xi, Shaanxi Province, was founded in 1950. It is also one of the earliest postal universities in China, with several national scientific research platforms and laboratories such as the Key Laboratory of Postal Equipment Technology.