Whether the pilot registration system reform can achieve the expected effect is related to the pace of China’s comprehensive implementation of the registration system reform. This paper selects the data of listed companies on the Science and Technology Innovation Board and the data of listed companies on the Growth Enterprise Market after the pilot registration system. At the same time, the data of listed companies before the GEM registration system reform were selected as a comparative sample. Using the stochastic frontier analysis to test the pricing efficiency of IPOs, this article finds that the registration system reform works well. It improves the efficiency of Chinese IPO pricing. Also, underwriter reputation has a negative impact on IPO pricing efficiency.