Abstract: Disscuss the factors and mechanism of open service innovation risk in platform enterprises through case analysis and grounded theory. The study founds that 9 main categories, 3 core risk category, as well as 2 risk consequences, constitute the risk mechanism of open service innovation in platform enterprises. The empirical study shows that business environmental risk, strategic risk and management risk have a great impact on platform innovation activities.These risk factors may result in customer churn and bussiness performance decline significantly.Business environment risk is the external risk platform facing,which has a obviously positive correlation with the strategic risk and risk management of platfrom.At the same time,strategic risk will increase the likelihood of management risk. The three risks are proportional to customer churn and inversely linked to the bussiness performance of platform enterprises.This paper extends the traditional management element model, reveals the risk interaction mechanism of innovation process in the Internet platform enterprise.