Following regional tourism cooperation, the promotion of balanced sustainable development has begun to play a vital role in the tourism industry. Using the West Coast of the Strait urban agglomeration, China, as an example, this study uses a data envelopment analysis (DEA) to analyzes the nonlinear relationship between tourism economic contact intensity and tourism industry efficiency by constructing a mixed effect model. The results show the following: (1) In the early stage of regional tourism cooperation, the efficiency of the tourism industry will decrease with an increase in the intensity of tourism economic contact. As regional cooperation tends towards a stable stage, the efficiency of the tourism industry will continue to increase with the strengthening of the intensity of tourism economic contact. (2) The regional economic level harms the efficiency of the tourism industry. The urbanization level has a positive effect on the efficiency of the tourism industry. (3) The level of opening up and transportation development in the region will not only bring tourism resources or tourists, but also lead them to flow out. They have no significant impacts on the efficiency of the tourism industry.