Mandrel shows a great influence on the quality of the tube during tube bending process. Especially, the selection of mandrel type directly affects the forming quality of the tube. In the paper, a 3D simulation model of stainless steel tube was established by finite element platform ABAQUS/Explicit. The influence of five kind mandrels on the quality of bended tube was investigated by simulation and experiment. It is found that the cylinder, round and arc mandrels show a great advantage in controlling the outer wall thinning compared with ball and round ball mandrels. Arc mandrel is benefit to reduce wall thinning of tube bending, while the ball mandrel exhibits the best performance among all the five kind mandrels during tube bending. The finite element simulation results show good agreement with the experimental results, and provide a theoretical guidance for the selection of the mandrel type in the actual production.