To discuss the effect of laser power on the uniform thickness of the thin-wall part fabricated by the Laser Direct Metal Forming (LDMF), the temperature field distribution was calculated by numerical simulation. The numerical results showed that the molten pool temperature and thickness of the thin-wall increases with the layer number when keeping laser power. In order to achieve a steady temperature distribution surrounding the molten pool, the laser power must be adjusted for each layer. According to the numerical results, the thin-wall part was fabricated by experiments. The experimental results show that the laser power should be changed with the layer number if a uniform thickness of the thin-wall part can be obtained, which is in agreement with the numerical simulation.