A semiconductor switch insulation protection device and a power supply assembly. Said semiconductor switch protection device comprises a semiconductor switch having a metal component, an insulation component, and a pin installed at a bottom plane of said insulation component, and an insulation protection cover having a body with a second hole and a side belt. A front surface of said metal component is installed on a back surface of said insulation component. A metal portion, with a first hole and having a first height, is extended above an upper plane of said insulation component. Said second hole and said side belt are extended toward a back surface of said body, respectively, to form a hole column having a second height and a sidewall having a third height. Said metal portion is disposed in a groove formed by said back surface of said body, hole column and sidewall.