Abstract: Current transformer is an important component of power system. In response to the policy of cost reduction and efficiency increase,the wall thickness reduction of 550 kV GIS current transformer shell was studied,and its comprehensive stress analysis was carried out. Firstly,various stresses on the current transformer shell in the most severe environment were obtained through theoretical analysis and calculation.Then,the deformation displacement and comprehensive stress of shell with different wall thickness under comprehensive stress were simulated and verified by simulation analysis software.The simulation results show that under the most severe operating conditions,when the minimum thickness of the shell after thinning can be12 mm,the maximum comprehensive stress of the shell is 56.3 MPa,which is less than the yield strength of the shell 90 MPa.The stress at the connecting screw of current transformer is 160 MPa,which is less than the yield strength of 640 MPa.The maximum displacement is 0.68 mm.And,the shell meets the requirements.Therefore,it is verified that the shell is not damaged,and the current transformer function will not be affected.After the current transformer device shell is thinned,the weight of a single shell can be reduced by 32.8%,which can achieve the effect of cost reduction and efficiency increase.