A disc locking device, comprising: a base, a brake clamping block, a support mechanism, a front baffle and a brake trigger mechanism; wherein the base comprises a bottom plate and two side vertical plates integrally formed on the bottom plate, the two side vertical plates are oppositely disposed, and inner walls thereof are lateral slope surfaces such that a wedge-shaped groove having a large front opening and a small rear opening is formed between the two side vertical plates, and each of the side vertical plates is provided with a mounting hole for connecting the brake trigger mechanism therethrough; the number of the brake clamping blocks are two and the two brake clamping blocks are juxtaposed in the wedge-shaped groove formed between the two side vertical plates on the base; a friction plate is disposed on a clamping surface of each brake clamping block, a back of each brake clamping block is a lateral slope surface, so that a body of the brake clamping block forms a wedge-shaped body, and the back of the brake clamping block is provided with a lateral chute for inserting a brake push rod; the support mechanism comprises a front support mechanism for laterally elastically pushing front portions of the two brake clamping blocks and a rear support mechanism for laterally elastically pushing the rear portions of the two brake clamping blocks; the front baffle is fixed at the front opening of the wedge-shaped groove of the base for preventing the brake clamping block from escaping from the front opening of the wedge-shaped groove; the brake trigger mechanism is connected to the brake push rod by a compression spring, and the brake trigger mechanism is mounted in the mounting hole of each side vertical plate, with the front end of the brake push rod passing through the mounting hole, its front end passes through a hole in the inner wall of the side vertical plate and abutting within the lateral chute of the brake clamping block; and wherein the disc locking device further comprises a needle roller slide plate, the needle roller slide plate is an L-shaped folded plate with a plurality of needle rollers being arranged in rows at the surface thereof; the needle roller slide plate abuts against a sidewall and a bottom of the wedge-shaped groove of the base for providing a sliding support for said brake clamping block. the base comprises a bottom plate and two side vertical plates integrally formed on the bottom plate, the two side vertical plates are oppositely disposed, and inner walls thereof are lateral slope surfaces such that a wedge-shaped groove having a large front opening and a small rear opening is formed between the two side vertical plates, and each of the side vertical plates is provided with a mounting hole for connecting the brake trigger mechanism therethrough; the number of the brake clamping blocks are two and the two brake clamping blocks are juxtaposed in the wedge-shaped groove formed between the two side vertical plates on the base; a friction plate is disposed on a clamping surface of each brake clamping block, a back of each brake clamping block is a lateral slope surface, so that a body of the brake clamping block forms a wedge-shaped body, and the back of the brake clamping block is provided with a lateral chute for inserting a brake push rod; the support mechanism comprises a front support mechanism for laterally elastically pushing front portions of the two brake clamping blocks and a rear support mechanism for laterally elastically pushing the rear portions of the two brake clamping blocks; the front baffle is fixed at the front opening of the wedge-shaped groove of the base for preventing the brake clamping block from escaping from the front opening of the wedge-shaped groove; the brake trigger mechanism is connected to the brake push rod by a compression spring, and the brake trigger mechanism is mounted in the mounting hole of each side vertical plate, with the front end of the brake push rod passing through the mounting hole, its front end passes through a hole in the inner wall of the side vertical plate and abutting within the lateral chute of the brake clamping block; and wherein the disc locking device further comprises a needle roller slide plate, the needle roller slide plate is an L-shaped folded plate with a plurality of needle rollers being arranged in rows at the surface thereof; the needle roller slide plate abuts against a sidewall and a bottom of the wedge-shaped groove of the base for providing a sliding support for said brake clamping block.