Abstract: The heat transfer of the SF-X05 multi-unit parallel-flow condenser of vehicle air condition during brazing in a furnace was analyzed. By defining different emissivity and convection heat transfer coefficient in different areas on the workpiece surface,the heat-flow density was characterized,and the algorithm for three-dimensional numerical simulation on the condenser was optimized. Meanwhile,the temperature field in the condenser during furnace brazing was analyzed. The comparison between the experimental and simulated results proves the accuracy of the developed finite element simulation program which provides an effective method to save experimental cost.