The maximum temperature rise of GW16-220 isolation switch under different contact conditions is discussed, and the relationship between contact temperature rise and isolation switch parameters is analyzed. The results show that the GW16-220 isolation switch is in a good clamping force range within the clamping force range of 450～600 N, and there is no significant change in contact resistance and temperature rise in this range. Contact temperature increases when load current increases. The fouling degree of contact surface has obvious influence on the steady temperature rise of the isolation switch. The difference between the maximum temperature and the minimum temperature will increase with the increase of the hot spot temperature. Under the static contact head the two sides have similar temperature rise law, and the lower slightly lower than the upper temperature rise.