Based on the finite element software,the performance of the hydraulic expanded joint of heat exchanger was analyzed.The effect of expansion pressure,material and initial clearance on the capacity and tightness of expanded joints was investigated.Results show that the capacity and tightness of expanded joints will be apparently enhanced with increasing pressures.Under the same pressure,the capacity and tightness of the joint of TA2 tube and TA2 tubesheet is better than the performance of the TA2-Q345R material combination.As the initial clearance is smaller,the residual contact pressure and pull-out force will decrease with the increasing initial clearance.As the initial clearance is larger,the residual contact pressure and pull-out force will retain a constant value regardless of the initial clearance.