In February 2021, extreme snow and cold weather hit the State of Texas, United States, and caused the Texas power grid blackout. Nearly 5 million electricity customers were hit with power outages. Industrial production and even human life were seriously threatened. This paper describes the basics of the Texas power system and how the Texas blackout evolved. The reason for the blackout is analyzed from the aspects of technology, management and organization. Suggestions for preventing power system blackout accidents are put forward, combining the development needs of power grid planning, in terms of strengthening power grid safety management and control, emergency response, power grid differentiation planning, emergency material reserves, etc. These suggestions can provide a reference for the power grid planner, operator and manager. This work is supported by the National Natural Science Foundation of China (No. 51707070) and the Science and Technology Project of State Grid Hubei Electric Power Co., Ltd. (No. 52153818001F).