According to the background of industry development and the characteristics of the electric vehicle enterprises, this paper designs an electric vehicle enterprises’ niche status efficiency evaluation system. The empirical analysis of China’s electric vehicle companies using the method of super data envelopment analysis indicate that the niche status efficiency is closely related to the use efficiency of complementary assets. The support resource factors such as the policy and financial support from government and the innovation resource factors such as scientific research personnel are the key complementary assets of electric vehicle enterprises’ niche and have an important influence on the diffusion of electric vehicle products.