"The research results show that the average years of education in primary school, junior high school and senior high school have significantly reduced the crime rate in China, and at the same time, its crime prevention effect has also been enhanced in turn. Among them, every increase of 1 year in primary schools can reduce the crime rate by 2.4 ~ 3.0 percentage points, every increase of 1 year in junior high schools can reduce the crime rate by 4.0 ~ 5.0 percentage points, and every increase of 1 year in senior high schools can reduce the crime rate by 5.4 ~ 6.5 percentage points. However, the average college education period of the labor force has no significant crime prevention effect. The main reason may be that education has the effect of preventing crime while improving people's chances of getting legal jobs and legal wages, and it may also improve crime productivity and crime income (Ehrlich, 1975), thus having the effect of crime expansion. For a high-level education like a university, its crime prevention effect and crime expansion effect may cancel each other out. In our country, the stagnation and decline of the legal rate of return of university education, on the one hand, inhibits the effect of university education to prevent crime by improving the legitimate income of workers; On the other hand; It may also lead those highly educated people who can't achieve the expected rate of return on education in the legal labor market to find jobs in the "illegal" labor market to obtain the expected rate of return, thus increasing the crime expansion effect of education, especially high-skilled crimes such as fraud, because highly educated people with higher human capital levels may have comparative advantages in engaging in high-skilled crimes (Lochner, 2004). According to statistics, since 198 1, the number of fraud crimes per 10,000 people and the proportion of fraud crimes in the total number of crimes in China have been rising continuously, especially after 2005, the growth rate is obviously faster, with an average annual growth rate as high as 1 1.8%. At the same time, the macro-educational background of the rise of high-tech crimes such as fraud in China is precisely 1999. After the expansion of colleges and universities in China, the phenomenon of "knowledge unemployment" and the unemployment of college graduates in the "legal" labor market have become more and more serious (Lai Desheng, Tian Yongpo, 2005). Now it seems that the above empirical facts may not be coincidental. "