In view of the problem of tour-guide service providers' moral hazard caused by asymmetric information in the tour-guide service outsourcing, designs the incentive mechanism for tour-guide service outsourcing based on the contract-issuing party participation and the principle-agent relationship between travel agency and tour-guide service provider. By analyzing the models of asymmetric information and information symmetry, discusses the incentive contract parameters of tour-guide service outsourcing and the optimal effort level relative factors of tour-guide service provider and travel agency. The results show that under asymmetric information, the effort level of tour-guide service provider and travel agency not only are affected by their own factors such as service capacity constraints but also are affected by other side factors and the uncertainty of tourism market. The tour-guide service provider with high service ability and willingness to undertake risks and responsibilities will get more earnings.