[Purpose/significance] With the advent of the era of paid knowledge, how to encourage high-quality content creators to contribute paid knowledge actively has become a problem for social Q&A community needs. Research on users' continuous knowledge contributing behavior is conductive to open new knowledge-paying market, and has practical significance for community long-term development. [Method/process] This paper regarded the social Q&A community Zhihu Live speaker as the research object. Based on motivation theory and perceived value theory, we explored the impact of social Q&A community users' paid knowledge contributing continuously factor through the negative binomial regression of real user data. [Result/conclusion] Live material rewards, psychological rewards, social capital, and the identity of the "pay for knowledge" concept have a significant positive impact, and the cost of knowledge compilation and users’ identity in community groups have a significant negative impact. High-threshold paid knowledge contributing behavior is not conducive to users' altruistic beliefs and self-efficacy.