Abstract: During the evolution of the power system towards higher voltage levels and larger capacity scales, temperature rise issues directly affect the operational safety and service life of switchgear, especially the heating phenomenon caused by eddy currents.To deeply explore the abnormal temperature rise of KYN28 switchgear in the cabinet area corresponding to the contact box, a mathematical model of temperature rise calculation was established based on magneto-thermal coupling mechanisms, and a three-dimensional simulation model was constructed to analyze the eddy current heating of the switchgear under 1.1 times the rated current as well as the temperature distribution law under different conductive structures and ambient temperatures.The results show that the heat source of the switchgear mainly comes from the ohmic loss of the conductive circuit, which accounts for about 66% of the total loss, and the ohmic loss on the shell is affected by the position of the conductor.In the conductive circuit, the temperature of phase B is higher than that of phases A and C,the temperature of the upper contact box is higher than that below, among which the temperature rise of the pole of the circuit breaker is the most obvious, the temperature of the bus bar is the lowest, and the local temperature near the bus bar area on the shell is abnormally increased.The simplification of the plum contact increases the equivalent resistance.It decreases the current, in-creasing the contact temperature, and the temperature distribution shows that the temperature at the end near the thin conductive rod is the highest.The temperature of the plum blossom contact increases approximately linearly with the increase in ambient temperature.The research results provide theoretical support for the design optimization of switchgear and the prevention of temperature rise faults.