Intelligent recommendation not only brings convenience to social Q&A communities, but also causes troubles. The influencing mechanism of knowledge contribution behavior in the context of intelligently recommended questions is worth attention. In the basis of existing Q&A data about ‘invitation to answer’ in Zhihu, this paper applies the grounded theory method to propose the question quality evaluation index in the context of intelligently recommended questions, and develop a ‘cognition-motivation-attitude-intention-behavior’ influencing mechanism model of knowledge contribution behavior based on intelligently recommended questions. Results show that cognition (question quality, question overload, and questioner reliability), motivation, attitude (affective state) and personality traits have direct impacts on knowledge contribution intention and behavior; motivation and attitude play mediating roles; process continuity is the guarantee condition of ‘intention-behavior’ path. This paper also provides suggestions on how to balance the relationship between questioners and answerers, new questions and answers in social Q&A communities.