In order to meet the requirement of axial force balance of mine rescue pump with high speed and big power, the capacity and reliability of water-lubricated thrust bearing of the pump unit should be improved. This paper presented a study on the capacity of water film and bearing bush deformation of water-lubricated thrust bearing based on the change of temperature in the motor chamber, which is under the actual operation condition of mine high speed rescue pump. In this study, the Reynolds equation was solved by MATLAB to get the thickness of water film, and the deformation of bearing bush was obtained through the joint solution of heat-fluid-solid coupling equation by ANSYS. The results show that the temperatures have little effect on the pressure distribution of water film and the deformation distribution of bearing bush. However, the maximum pressure of water film increases with the temperature. The research of the paper could provide theoretical support and technical guidance for the design of water-lubricated thrust bearings under big power and high speed conditions in the future.