Abstract: Annular linear induction electromagnetic pump (ALIP) is key component in the liquid metal reactor primary systems, and accurate evaluation of the winding coil temperature field is a prerequisite for their thermal hydraulic design and safety assessment. Existing studies usually treat the multiturn layer wound excitation coil as a homogeneous solid in thermal analysis and assign an empirical bulk thermal conductivity, which lacks theoretical and computational consistency with the actual coil geometry and electromagnetic parameters, and is insufficient for high temperature and high power operating conditions that require both accuracy and efficiency. Therefore, this study aims to develop a winding equivalent thermal conductivity determination method dedicated to ALIP, to couple electromagnetic design parameters with thermal analysis parameters in a self-consistent manner and to provide a theoretical basis for the reliable high temperature operation of electromagnetic pumps in liquid metal loops. To achieve these objectives, the equivalent circuit method was adopted to model the resistances of the inner magnetic core, the liquid metal flow channel, and the inner and outer conductive walls, and calculated the branch currents of the ALIP. Loss power models for Joule heating in the copper windings, iron losses in the magnetic core, and eddy current losses in the liquid metal and conducting walls were then established, and all these losses were treated as internal volumetric heat sources in the radial heat conduction problem. Taking advantage of the quasi-axisymmetric nature of the ALIP and the fact that the radial temperature difference is much larger than the axial one, the multiturn helical winding was simplified into a multilayer concentric cylindrical structure. A one dimensional steady state radial heat conduction equation set was formulated from the pump center outward through the inner core, inner wall, liquid metal, outer wall, thermal insulation, copper conductors, and multiple insulation layers, and the temperature field of the multilayer cylinders was solved analytically using recursive interlayer temperature relations. The real winding structure was further reduced to a single cylindrical body with uniform internal heat generation and an unknown equivalent thermal conductivity, and this equivalent thermal conductivity was iteratively adjusted until the channel averaged temperature calculated by the simplified model matched that of the full coil model at the target operating temperature, so that the equivalent thermal conductivity of the winding assembly could be obtained for different operating conditions. To validate the methodology, a commercial finite element multiphysics solver was used to build both the detailed three dimensional ring coil model and the equivalent thermal conductivity model, six mesh schemes were designed for each model, mesh independence was verified using the channel averaged temperature as the monitoring quantity, and the radial temperature distributions and channel averaged temperatures predicted by the two models were compared at several operating temperatures between 300 °C and 600 °C. The results show that, within the investigated operating range, the proposed winding thermodynamic simplified model based on equivalent thermal conductivity reproduces the radial temperature profile of the detailed ring coil model with engineering level accuracy, and the relative deviation of the channel averaged temperature remains within acceptable limits. As the ALIP operating temperature increases from 300 °C to 600 °C, the equivalent thermal conductivity of the overall winding structure varies from approximately 1.29 W/(m·K) to 1.38 W/(m·K), exhibiting a slight increasing trend and being significantly lower than the value obtained by simply taking the copper thermal conductivity for the entire coil. The equivalent thermal conductivity model maintains essentially the same accuracy in predicting the temperature field while reducing the mesh count of the winding region from 14 604 to 2 011, a reduction of 86.2 %, which greatly decreases the computational cost and improves the robustness and convergence of multiphysics simulations. Overall, the study demonstrates that the proposed equivalent thermal conductivity model, which couples the equivalent circuit formulation with one dimensional radial heat conduction, provides a physically grounded yet engineering friendly modeling strategy for complex winding structures operating at high temperatures in liquid metal loops and offers a practical and valuable tool for the thermal design, performance optimization, and safety analysis of ALIP.