Public policy is the new sources of technology innovation. In spite of promoting technology innovation, some public policies can also trigger patent race and enhance the density of patent thickets, even hinder technology transfer and diffusion. The patent policy in the key special project of scientific instruments is analyzed by using the method of case study in order to explore whether our country’s policies can resolve the patent assembly problem. Results show that there is the risk of failure in patent assembly due to the neglect of background patents, though this policy has paid attention to patent assembly problem and endeavored to resolve this issue. Finally, the suggestion that policy makers should take ex ante measures to resolve the risk of patent assembly failure is put forward in order to promote policy-led incentives for innovation.