The formation of an integrated technology market cannot be separated from intercity cooperative innovation, which is the basic guarantee for achieving cross-regional collaboration in scientific and technological innovation and industrial innovation, as well as the key to optimizing the balanced distribution of innovation resources and technological factors at the spatial level. It is also a necessary path for building a unified national technology market.

In this context, this paper constructs intercity population mobility indicators with the help of Gaode map, Tencent map, and Sina Weibo geo-tagged big data, and combines the data of intercity collaborative patent applications to investigate the impact of intercity population mobility on intercity cooperative innovation. The results show that intercity population mobility increases the number of intercity collaborative patent applications, and this effect is stronger in cities with greater geographic distance, economic distance, and institutional distance. Mechanism testing shows that breaking through the invisible barrier of cultural differences is a channel of action for intercity population mobility to promote intercity cooperative innovation, which is reflected in the fact that intercity population mobility promotes intercity cooperative innovation by decreasing cultural differences, and then enhancing bilateral trust and improving social inclusiveness. Further examination reveals that an increase in the number of intercity cases of breach of trust weakens the promotion effect of the cooperative innovation of intercity population mobility.

The policy recommendations are as follows: First, we should improve the equalization level of public services, deepen the construction of new urbanization centered on human beings, and unleash the potential for cooperative innovation of population mobility. Second, we should reduce the invisible barriers of cultural differences, improve the level of inter-regional trust and social inclusiveness, and reduce the invisible costs of intercity cooperative innovation. Third, we should improve the construction of the social credit system, and reduce the number of cases of intercity mobility with breach of trust.