Internet has revolutionized business model and given birth to sharing economy. A large number of platform enterprises are growing rapidly but with sustainability problems. Platform enterprises have to continue innovating business models in order to obtain sustainable competitive advantages. In complex and varying environment, dynamic capabilities help enterprises overcome core rigidity and promote business model innovation. This article analyzes the elements of business model innovation of platform enterprises and also the relationship between dynamic capabilities and business model innovation. It concludes that the elements of business model innovation are value proposition, product, partnership, and profit model innovation. Dynamic capabilities promote business model innovation which has different guiding effects on the cultivation of dynamic capabilities. An exploratory case study was conducted, using DiDi taxi as an example, and verified the theory model.