Based on the competitive and information mechanisms of enterprise strategic decision making, taking A share listed companies in Shanghai and Shenzhen from 2008 to 2020 as research samples, this paper explores the group characteristics and influencing factors of enterprise innovation investment. We find that the innovation investment of enterprises in the peer firm can significantly promote the innovation investment of focal enterprises, that is, the innovation investment of enterprises exists in the city peer effect. The market position of focal enterprises and the geographical distance between focal enterprises and peer enterprises will weaken the city peer effect where enterprises invest in innovation. The analyst attention of peer enterprises and the diversity of professional background of management in focal enterprises will strengthen the city of peer effect where enterprises invest in innovation. Heterogeneity analysis tests show that the property rights attributes of state owned enterprises weaken the city peer effect of enterprise innovation investment, while the high tech attributes of enterprises and the innovation environment of the location strengthen the city peer effect of enterprise innovation investment. Tests of economic consequences show that the city peer effect of enterprise innovation investment can increase enterprise patent output and market value. This article not only enriches the research on the driving factors of enterprise innovation investment, but also provides useful ideas for promoting innovation driven development strategy.