Service Supply Chain (SSC) have seen considerable attention in the business circles and academia. However, little focused on Service Integrator (SI), especially the research results about SI competitiveness and its influencing factors in the context of SSC has not yet appeared. This paper study the formation mechanism of Service Integrator competitiveness (SIC) under the perspective of SSC and its influencing factors of structural model. Data collection consisted of an network questionnaire survey and resulted in 252 usable responses. Research results show that collaborative capability (CC), integrating capability (IC1), organization capability (OC) and innovation capability (IC2) coupling form SIC and came into being the important influencing factors of SIC. Innovation capability intermediary effect significantly and constituted the important way of SIC. Low cost and high service differentiation constituted a competitive advantage of SI.