Regarding the characteristics of policy mix and its effectiveness, no complete consensus currently exists. This paper divides the new energy vehicle (NEV) industry policies issued by the Chinese government from 2009 to 2018 into two types: the supply-side and demand-side policy mix. From the three dimensions of comprehensiveness, consistency and balance, we applied the state space method to construct a time-varying parameter model and analyzed the differences in the overall and dynamic impact of the NEV policy mix characteristics on market growth. The results show that the three characteristics differ in their overall impact: comprehensiveness has the largest impact, followed by consistency, and balance has the smallest impact. The dynamic impact of the comprehensiveness and consistency characteristics of the two types of policy mix fluctuates greatly and presents clear differences in the stage effect. The dynamic impact of the balance characteristic is relatively stable, but this characteristic has little dynamic impact on market growth. The NEV industry policy design should fully consider the characteristics of the policy mix and the differences of this policy mix in terms of market development stage and region.