High technology industry with high risks and high profitability, it is because of these characteristics has attracted a lot of risk investment, the government as the main support of high technology industry, the integrated use of fiscal means such as tax and investment and financing to adjust the relationship between venture investors, venture capital company and venture enterprise. This paper introduces the two-period of partial equilibrium model, and analyses the question that how risk investment policy work on high technology industry with three aspects ranging from tax mechanism of risk investment behavior, mechanism of governmental risk investment policy to venture investors, to the influence of the tax policy for high technology enterprise on risk investment mechanism. And it points out that the governmental taxation type and tax base will affect the risk investors' desire and high technology enterprise cost of capital, which influence the development of the high technology industry.