With the application of advanced computer and communication technologies, modern power system transformed into cyber-physical power system (CPPS). CPPS is critical infrastructure for modern society, which has complex dual-direction information flow. The information interactions make CPPS vulnerable to cyber-attacks, resulting in serious consequences in extreme cases. Some power system blackouts accidents had occurred around the world in recent years, such as Ukraine blackouts in 2015 and Venezuela blackouts in 2019. Consequently, it is necessary to summarize and analyze cyber-attack methods on CPPS for the defense against cyber-attacks. In this paper, a review of cyber-attack methods on CPPS is summarized and analyzed. Firstly, this paper summarizes the principles of different cyber-attack methods, such as false data injection attack (FDIA), denial-of-service (DoS) attack and man-in-the-middle (MITM) attack, etc. Secondly, the paper analyzes the applicable scenarios of different cyber-attack methods and studies possible attack methods on equipment and systems such as state estimation, wide area measurement systems (WAMS), smart meters and so on. Finally, according to the characteristics of different attack methods, some defense strategies are presented to against cyber-attacks.