As a result of the rapid advancement in information and communication technologies, learning cyberspace has become a channel for teachers to share learning resources. This study explored the influencing factors of learning resource sharing in teacher learning cyberspace. The study sample consisted of 363 high-quality teacher learning cyberspaces that had received platform awards from 2015 to 2019, among which 41% of cyberspace owners were male (N = 149) and 59% were female (N = 214). The number of space-associated friends, space follows, space followers, space messages, resources spread, space visits, community contributions, external rewards, the proportion of original resources and uploaded resources, which were collected by the web crawler technology were taken as measurement dimensions. The results of structural equation model indicated that trust positively correlated with learning resource sharing, while self-efficacy and reciprocity were not significantly related to learning resource sharing. In addition, it was shown that trust affected self-efficacy and reciprocity dramatically. Based on this, the trust level of teachers in learning cyberspace can be improved by adding the function of friend circle, setting up effective incentives, and copyright protection mechanisms to facilitate teachers' learning resource sharing.