The purpose of this paper is to reduce the risk accidents caused by incorrect subjective risk cognition in the process of physical exercise, and promote the physical exercise of the middle-aged and elderly to be more scientific, sustainable and healthy. Methods qualitative research and questionnaire survey were used to make an empirical study on the risk of physical exercise of middle-aged and elderly people in China. Results the risk cognitive structure of physical exercise in the middle-aged and elderly included risk benefits, risk concerns and measures to deal with risks. Its characteristics included irrationality, degree of control and degree of stability; The cognition degree of physical exercise risk of middle-aged and elderly people includes uncertainty, ability to control and risk. The risk cognition degree of most middle-aged and elderly men is deeper than that of women; Self behavior, risk control, self conditions and risk knowledge are the main factors affecting the risk cognition of physical exercise of the middle-aged and elderly. Conclusion there is no difference in the risk judgment of most physical exercise among the middle-aged and elderly people with different gender and experience; The middle-aged and elderly people of different ages have obvious differences in the judgment of some physical exercise risks.