The invention discloses a power module and a power conversion device. The power module includes a primary converting unit including a first active device unit; a secondary converting unit including a second active device unit; a transformer including a primary unit connected to the primary converting unit and a secondary unit connected to the secondary converting unit; a first heat dissipating unit on which the primary unit and the first active device unit are disposed; a second heat dissipating unit on which the secondary unit and the second active device unit are disposed; and an insulating plate including an insulating plate body and a semi-conducting layer disposed on a surface of the insulating plate body.