Prefabricated buildings are gaining momentum due to their ecological benefits, speedy construction, and precision. However, unlike conventional cast-in-place structures, precast concrete shear walls are more susceptible to thermal and quality defects due to inherent tolerances. Four precast concrete shear wall connections prone to thermal bridges were identified through case studies of factories and real projects. Steady-state and dynamic modeling was conducted using determinant and stochastic matrices to assess the impact of joint tolerances on thermal distribution. The effects of joint tolerance magnitude and insulation material properties on linear thermal transmittance were investigated, complemented by a polynomial-based sensitivity analysis. A versatile prediction model was developed, integrating physical modeling and data-driven approaches to quickly quantify the thermal bridges of precast concrete shear wall connections. The results revealed a significant positive correlation between thermal bridges and joint tolerances, leading to extensive low-temperature regions within precast concrete shear walls. In dynamic modeling, joint tolerances contributed to additional heat dissipation, with a peak heat flux of 20.07 W/m. The sensitivity analysis demonstrated that joint tolerances greatly influence the correlation between linear thermal transmittance and insulation layer properties. Leveraging Categorical Boosting and Extreme Gradient Boosting, the prediction of linear thermal transmittance for precast concrete shear wall connections exhibited exceptional accuracy while significantly reducing computational costs. This research aids designers and policymakers by providing rapid and precise linear thermal transmittance calculations, offering valuable guidance for manufacturing prefabricated components to ensure enhanced energy efficiency and sustainability.