In this work, SS/ceramic composite material was produced by laser welding with active filler (AgCuTi). The presence of the AgCuTi filler was determined by ensuring that crack-free welds were obtained, and no brittle intermetallic compounds (IMCs) were observed. Unmelted SS was retained by laser offset to the SS side to achieve heat transfer to the filler. The AgCuTi filler was not melted but the eutectic reaction with low melting point still occurred by atomic diffusion. In accordance with the characteristics of laser brazing, a mathematical model for calculating the transient heat transfer of laser brazing was established via finite element method. The simulation results showed that the interface temperature could be directly controlled by controlling the welding power.