It is necessary to use the thermal network method for thermal analysis of the bearing, but there are still some shortcomings. In this paper, a novel thermal network model of the bearing transient temperature is developed considering the thermal-fluid-solid coupling effects. First, the quasi-static analysis of the bearing is carried out considering the thermal expansion effect, and the heat generation, heat transfer, and heat dissipation are studied. Then, the coupling effects between the oil characteristics, heat generation, structure parameters, and temperature (thermal-fluid-solid) during the operation of the bearing are discussed, and the transient thermal network model of the bearing-shaft-bearing housing system is established. Test results indicate that the existing models (without thermal-fluid-solid coupling) have large temperature deviation, while the proposed model in this paper considering the thermal-fluid-solid coupling effects is much more accurate. Finally, the effects of rotational speed, load, oil temperature, and oil flowrate on the temperature rise are all achieved and discussed.