Abstract: The flow field of cavity with fuel supply injection located at the forebody and afterbody in trapped vortex combustor(TVC) was studied using particle image velocimetry(PIV) testing technology.In order to study the influence of fuel supply position on the formation of vortex and vortex stability,different incoming flow velocities and fuel supply locations were analyzed.The results show that,when the fuel supply position is located at the forebody of cavity,the jet flow of fuel supply has certain damage to vortex,and when the fuel supply injection is located at the afterbody of cavity,the jet flow of fuel supply has no damage to vortex.These results provide the fundamental proof for the further studies on the combustion properties of this TVC test rig.