A good stock market environment is not only related to the future development direction of an enterprise and the improvement of the quality of the current enterprise, but also to the strategic planning of China's economic development, and directly to the gains and losses of investors in the stock market. Investors' trading behavior is an important factor affecting market stability. In observing the trading behavior of small and medium-sized investors, we find that irrational buying and selling behavior is widespread, which amplifies the fluctuation of stock prices and affects the stable development of the stock market. This article analyzes the situation of small and medium investors and their irrational investment behavior one by one, and gives some targeted suggestions. <<