The high temperature superconducting ultra-high voltage (HTS-UHV) synchronous condenser boasts advantages such as high power density, rapid response, and large short-circuit capacity. Its stator typically employs a non-magnetic tooth and Litz wire design to minimize losses, making thermal characteristic research crucial for ensuring stable operation and optimized performance. First, this paper designs a 28.2 Mvar HTS-UHV synchronous condenser and conducts analytical calculations on the electromagnetic characteristics, losses, and temperature field of the stator side. The condenser has a rated voltage of 35 kV, enabling direct grid connection without a transformer. The stator adopts a non-magnetic tooth combined with Litz wire structure, while the rotor utilizes high-temperature superconducting materials for excitation. Next, the paper employs analytical expressions to identify key factors influencing AC losses in the stator-side Litz wires. Finally, under ultra-high voltage conditions and targeting temperature compliance with Class F insulation requirements, the study optimizes Litz wire specifications through coupled electromagnetic-thermal field analysis while considering manufacturing constraints. This provides technical support for the motor’s optimized design.