From the Angle of enterprise external knowledge search, this paper discusses how service companies through cross-border open and exploratory search for knowledge in order to realize the organization learn quickly and complete product innovation, which has a important practical significance to promote our country enterprise innovation ability. This research bases on "the service enterprise how to improve product innovation through knowledge search absorption performance" , Comprehensive analysis using the previous method and inheriting predecessors research results to build model of the search for knowledge, absorptive capacity and product innovation performance relationship, revealing the knowledge search on product innovation performance mechanism of the black box.