Hot-bar soldering (pulse reflow soldering) is widely used in the automated welding of micro-scale electronic components, where high requirements are imposed on both the temperature ramp rate and temperature control accuracy. Conventional control methods establish process models based on time-domain assumptions or equivalent analyses; however, model mismatch may result in temperature overshoot and degraded system stability. In this study, parameter identification is carried out based on nonlinear least-squares estimation, and an extended state-space model for temperature control of the hot-bar soldering process is established. An model predictive control （MPC） controller is designed, and the closed-loop simulation of the hot-bar soldering temperature control system is performed. Simulation results indicate that, compared with the conventional proportional-integral-derivative（PID） and Smith-PID controllers, the MPC controller exhibits stronger robustness under model mismatch and achieves superior disturbance rejection performance under external perturbations. Micro-cable welding experiments demonstrate that the MPC controller exhibits good temperature regulation performance, achieving a temperature rise rate of up to 240℃/s while significantly suppressing temperature overshoot. The temperature control accuracy during the welding process reaches ±2℃. After replacing welding heads with different structural sizes, the temperature control performance remains essentially unaffected, achieving precise temperature control of the hot-bar soldering process.