Abstract: The calculation of the core temperature of the cable joint is an important part of the cable current carrying capacity prediction. In this paper,the heat dissipation path of the three core cable joint is analyzed according to the joint structure. Furthermore,an improved heat path model considering the axial heat dissipation is proposed. Taking the middle joint of the 10 k V three core cable as an example,the finite element temperature field calculation is carried out,and the parameter identification of the steady-state thermal circuit model is realized according to the temperature response. The equivalence of the steady-state thermal circuit model under different cable currents and environmental heat dissipation conditions is analyzed,which is found to be in good agreement with the finite element simulation results. The model can effectively improve the efficiency of hot spot calculation of cable joints.