In metal-cooled fast reactors, electromagnetic pumps are often used to drive the flow of liquid metal coolants due to their advantages such as no moving parts, good sealing, simple structure, and reliable operation. The coil winding inside the electromagnetic pump can generate a traveling wave magnetic field when supplied with three-phase alternating current, thereby driving the flow of liquid metal fluid. As an important component of the electromagnetic pump, its operating temperature is often a focus of attention. However, due to the structural characteristics of the electromagnetic pump and its working conditions, obtaining the temperature distribution inside the pump body through experimental methods is quite challenging. Therefore, this paper employs numerical simulation methods to establish a three-dimensional model of the ALIP electromagnetic pump. It analyzes the distribution characteristics of the internal temperature field of the ALIP electromagnetic pump when operating in a vacuum environment, specifically when heat is dissipated to the external environment solely through radiative heat transfer. Additionally, the effects of the temperature of the liquid metal coolant inside the electromagnetic pump, the heating power of the coil winding, and the external environmental temperature on the temperature of the coil winding are analyzed under these conditions.