Since P2P online loan companies were born in China in 2007, investing in loan products on P2P platforms has become a new form of wealth management for many people. Through a questionnaire survey, this paper finds out that although there are no obvious changes in the effect and adjustment factors based on the existing perception risk factors and adjustment factors theory, most investors' investment in P2P periodic loan products continues to grow. This shows that in the process of investment, there are other factors that significantly affect the risk perception of investors. This study uses qualitative research methods to sum up the investor's investment decision and its perceived risk change model, and explores the relationship between investment behavior and perceived risk. According to this study, the long-term investor's perceived risk lies between the tentative risk R1 and the objective risk Ri; the investor does not passively make risk judgments from external information, but actively measures the size of the risk through actual investment behavior. After an investor has made his first investment, his own investment experience is an important factor in measuring the risk; P2P companies can acquire users and enhance business competitiveness by attracting users to make tentative investments and fulfill service commitments during their trial period.