Taking the survival and development of P2P enterprises as the standpoint, this paper explores the driving factors of P2P trading volume and path mechanism of co-evolution among variables in the aspects of supply-demand mechanism, borrowing rate and word-of-mouth. It arrives at the following conclusions: firstly, financing demand and investment demand are two key driving factors for P2P platform performance; secondly, the increase in borrowing rate does not result in the rise in trading volume; on the contrary, with the increase in P2P trading volume, the borrowing rate reduces instead, which is consistent with the reality and to a certain extent shows that the development of P2P enterprises is becoming more and more rational; thirdly, negative word-of-mouth does not have the significant effect on P2P trading volume, showing that there is the rigid demand for P2P from one aspect; in addition, with the increase in P2P trading volume, negative word-of-mouth of P2P platforms also rises, implying that customer experience in P2P industry is poor and there is plenty of room for improvement in services quality and word-of-mouth construction. Finally, it proposes an integrated framework, which helps to understand the path mechanism of co-evolution among variables and to some extent is of practice significance to the grab of key elements by guiding P2P enterprises and the improvement of P2P platform performance.