High-tech companies can obtain a patent and commercialize it; or directly commercialize it after successful Ｒ＆Ds in secret without a patent． From the view of limited ration，considering the actual psychological feelings of the investors of venture capital and the characteristics of high-risk and multi-stage capital injection in the high-tech project of high-tech companies，the paper establishes a dynamic，multi-stage investment decision evaluation model based on limited ration，real option and different technology strategies． The proposed model factually and inclusively evaluates the high-tech projects and supervises the venture capital investment decisions． The model provides its parameters value and the influences of all parameters are analyzed．Some policy suggestions are provided in the end．