关键词: 共享经济，汽车租车行业，竞争战略，波特五力模型，风险管理 。
With the rapid development of the emerging technologies, such as mobile Internet, mobile payment, big data, Internet of Things and artificial intelligence, the concept of sharing economy has penetrated people's hearts and affected all aspects of people's lives, which promotes rapid development of shared economic enterprises. Under the condition of shared economy, the competition among enterprises has surpassed the price competition and market competition of thetraditional enterprises, continuously shifted toward the core competitiveness and competitive advantage of enterprises. C enterprise of the rental industry is no exception. The car leasing business is always the core business of the enterprise, which is closely related to the development of the sharing economy and Internet technology. If C enterprise wants to gain competitive advantage in the fierce competition of car rental market, it is important for C enterprise to carry out strategictransformation according to the characteristics of the sharing economy and the company's own situation, to determine a reasonable company competition strategy, which will promote the enterprise's own healthy and sustainable development. Therefore, the research of the thesis has practical significance.
In the thesis, based on the characteristics of shared economy and method of enterprise strategic management theory and method, Porter’s Five Forces Model Analysis is firstly carried out, and the differentiated strategy + cloud strategy that is the enterprise's future competitive strategy is determined. Then from the aspects of laws and regulations, market competition, business development, business pricing and technology update, the risks of the enterprise's competitive strategy are analyzed, which clarify the impact of various risks on enterprise's strategy implementation in the future. In addition, the risk countermeasure are proposed from various aspects, which include expanding business scope, focusing on the development of third and fourth tier cities, establishing diversified business models, cooperating with various industries under various existing business models and providing diverse services etc. The research results of the thesis provide theoretical support for the implementation of enterprise's competitive strategy and the improvement of competitive strength. The main contents of the thesis are as follows:
（1）In the formulation of the company's competitive strategy, Porter Five Forces model is used to analyze the industry competition situation of Car rental industry. According C enterprise's vision, strategic goals and its own advantages, the competition strategy adopted by C enterprise was given.
（2）In the risk analysis on the implementation of the enterprise's competitive strategy, the risk factors are classified into laws and regulations, market competition, business development, business pricing, financial management and business models, technology, management coordination, human resources and others. The impacts of the risk factors are analyzed.
（3）For the risk countermeasures in the implement process, the corresponding countermeasures, such as further developing its leading edge, cooperating with partners, expanding its business scope, continuously strengthening international cooperation, improving its car rental service system, training outstanding talents are given.
Keywords: Sharing economy, Car rental industry, Competitive strategy, Porter's five-force model, Risk management。