Tourism symbiosis is a social phenomenon consisting of many complex factors, and the reciprocal cooperation among multiple tourist agents at tourist destinations is the crux of the sustainable development of tourism. This study is from the perspective of tourist enterprises, and introduces the Symbiosis Theory of genecology. A quantitative evaluation is used to analyze both the equilibrium state of the combined symbiotic behavior routes and the behavior patterns of tourist enterprises with local governments, community residents, tourists and tourist enterprises around Qinghai Lake. The findings reveal: (1)the symbiotic behavior routes of the multiple tourist agents “E→G-R-T-E” in the Qinghai Lake area are constituted of intense symbiotic indications, while the maximum dimensionality of symbiotic interest of “E→G-R-T-E” is still in the state of disequilibrium and dissymmetry; (2)the symbiotic model of multiple tourist agents “E→G-R-T-E” in the Qinghai Lake area is an asymmetrically positive symbiotic model. It is proposed that, by establishing symbiotic mechanisms for guidance, decisions, supervisory control and profit distribution, the participation mechanism for multiple agents “E-G-R-T” can be further standardized. Moreover, tourist enterprises should be regarded as the primary agents to optimize the symbiotic model for “E→G-R-T-E” through the reinforcement of integrative supply and the construction of integrative effect, and finally promote the integrative symbiotic model of symmetrical reciprocity of the E-R-G-T model “driven by scenic areas, responsive to community residents, affected by local governments and enjoyed by tourists.”