R&D expenditure can reflect the behavior and result of technological innovation. By analyzing the influence of market value of technological innovation and government resource support on R&D expenditure scale and different stage scale, the mechanism and effect of market and institutional factors on technological innovation behavior is studied. The test of 297 high-tech private enterprises in small and medium-sized board shows that the value of technological innovation has a significant positive impact on capital and expense R&D expenditure. Financial subsidies significantly regulate the positive relationship between technological innovation value and capital or expense R&D expenditure, and the regulatory effect on the former is greater than that on the latter. Tax incentives do not have significant regulation effect on the relationship between the value of technological innovation and capital or expense R&D expenditure. Financial subsidies have a better driving effect on high-tech private enterprises.