It is demonstrated that, in the surface plasmon resonance (SPR) detection system, the thermal effect generated by the variation of environmental temperature will affect the resonance condition and correlated output. The SPR detection system based on the liquid prism is set up, in which the thermal performance of each dielectric layer is analyzed in detail. Based on the theoretical model on the relationship between the refractive index of the dielectric layer and the temperature, the influences of the environment temperature variation on both the resonance curve and resonance angle of each dielectric layer are numerically simulated. The simulated results show that the thermal effected refraction variation of deionized water are 1-2 orders higher than that of glass substrate and metal film. By exploiting self-build resonance detection system, we experimentally explore the dependences of both the resonance angle deviation and the refractive index change of water on environmental temperature variation. The results indicate that when the variation range of the environment temperature is 29 K, the resonance angle offset is 0.216° and the refraction change of the water reaches up to 4.02×10 -3. Also, the formula of the relationship between the refraction of the water and the temperature is attained. The experimental results basically agree with the theoretical calculations, which lay foundation for further improvement of the sensitivity of the detection system.