With the continuous development of the times, the business scope of the nancial market is also expanding, and more and more unknown risks have emerged in the process of development, which has brought a certain impact to the nancial market. The exchange rate uctuation, interest rate and other factors related to the international nancial market make nancial market risk one of the important risks faced by securities companies. Therefore, securities companies need intuitive, accurate and effective quantitative management tools for nancial market risk assessment to improve the overall risk management level of the company. Therefore, this paper constructs a nancial market risk prediction system based on computer data simulation technology and Markov chain Monte Carlo algorithm. This system is mainly composed of three parts: nancial risk management, data exchange management and background risk application services. The front end of the nancial market risk prediction system is divided into risk monitoring, risk allocation, risk report, risk decision-making and system log modules according to functions. Data collection management functions mainly include data collection, data encryption, data conversion, data return and other functions. The measured results show that the system can predict the signi cant in ection points in most economic risks synchronously or in advance, and the forecast data shows that the nancial security index has an upward trend from bottom to top. In this paper, the Markov chain Monte Carlo algorithm is introduced into the nancial market, through data simulation to predict the risks of companies with economic risks, and make a small contribution to the market development.