The temperature field of the wellbore in electric heating viscous oil thermal recovery is recognized as a critical factor in designing thermal recovery operation parameters. The core objective of thermal recovery technology is to enhance crude oil fluidity by reducing its viscosity, which is highly sensitive to temperature, making thermal recovery methods a focal point in the industry. A numerical model was established using MATLAB software based on heat transfer theory and the law of conservation of energy, with the influence of temperature on the thermal properties of viscous oil considered. Numerical calculation methods for the wellbore temperature field in continuous electric heating and segmented electric heating processes were proposed. The effects of electric heating, insulated tubing, and viscosity reducers on the wellbore temperature field were calculated using the control variable method, both individually and synergistically. Results show that the parameters of electric heating and insulated tubing significantly affect the temperature field of viscous oil, while the direct impact of viscosity reducers is relatively minor. Optimization of electric heating power, heating depth, and insulated tubing depth was conducted for Well 119X61 in Gudao Oilfield using a multi-objective genetic algorithm, and energy consumption and costs were significantly reduced while the wellbore lifting temperature was ensured. This study provides new perspectives and technical references for the selection of thermal recovery processes and the design of operation parameters in viscous oil wells.