The invention relates to a transporting device and a pre-mounted-type transformer substation. The transporting device comprises a towing vehicle and a loading platform with wheels. A towing seat usedfor being connected with a towing connecting structure on the pre-mounted-type transformer substation is arranged on the towing vehicle. A connecting structure used for being detachably and fixedly connected with the pre-mounted-type transformer substation to constitute a towed traveling device with the pre-mounted-type transformer substation jointly is arranged on the loading platform. The transporting device comprises the towing vehicle and the loading platform with the wheels, the towing seat used for being connected with the towing connecting structure on the pre-mounted-type transformer substation is arranged on the towing vehicle, and the connecting structure used for being detachably and fixedly connected with the pre-mounted-type transformer substation to constitute the towed traveling device with the pre-mounted-type transformer substation jointly is arranged on the loading platform; and the pre-mounted-type transformer substation on an engineering site is convenient to dismount, and the pre-mounted-type transformer substation can be quickly mounted to be used as a fixed transformer substation for a long time.