The invention discloses a convenient-to-maintain frequency changer which comprises an upper cover, a bottom shell, a radiator, an electronic device, a power board and a control board. The radiator is fixedly mounted on the bottom shell through a fastening member, a fixing member and a radiator fixing member, a clamping groove is arranged on the fixing member, the radiator is inserted into the clamping groove through an insertion-type connecting member which is fixedly arranged on the radiator through the fastening member, the upper end of the power board is fixedly arranged on the insertion-type connecting member through a fastening member after being matched and positioned with a positioning column arranged on the bottom shell through a U-shaped groove, the upper end of a first protecting cover is fixedly arranged on the insertion-type connecting member through a fastening member after being matched and positioned with the positioning column arranged on the bottom shell through the U-shaped groove, and two sides of a second protecting cover are arranged on the radiator fixing member through the first protecting cover and a supporting frame. The convenient-to-maintain frequency changer is convenient to demount and maintain and flexible in wire incoming and outgoing, and loss caused when the frequency changer stops is reduced furthest.