A three-dimensional finite element model has been created to study the change rules of temperature field during the laser sintering process of nano-hydroxyapatite powder. The numerical simulation of temperature distribution has been achieved based on the equivalence between the sintering time and the sintering speed. The simulation results show that the temperature declines gradually along the radial direction of the laser spot. At the same time, there was the largest temperature gradient at the edge of the laser spot. The temperature of sintering layer rises with the increase of laser power linearly when the other process parameters are the same. The maximum sintering temperature is 1320°C with laser power of 8.75W, laser spot diameter of 4mm, sintering time of 5s and layer thickness of 0.2mm. The test results verify that nano-hydroxyapatite powder could be sintered under this process condition. It shows that the finite element model can be used to simulate the temperature field during the laser sintering process.