Disclosed is a detachable suspension clamp of an overhead conductor rail. The detachable suspension clamp consists of a suspension frame, a slidably-detaching clamp and a tightly-pushing block, wherein a mounting boss is arranged on the top end of the suspension frame; an anti-detachment boss and guiding rod holes are arranged in the suspension frame; a slidably-detaching platform mounting hole and spring sleeve holes are arranged on the suspension frame; a slidably-detaching platform is arranged on the top end of a body of the slidably-detaching clamp; overhead conductor rail clamps are fixedunder the body of the slidably-detaching clamp; the lower part of the slidably-detaching platform is provided with an inclined plane I; the lower part of the tightly-pushing block is provided with aninclined plane II matched with the inclined plane I; the slidably-detaching platform is inserted and mounted in the suspension frame through the slidably-detaching platform mounting hole; the tightly-pushing block is mounted on guiding screw pairs in a sleeving manner and is capable of sliding freely; the guiding screw pairs are mounted in the guiding rod holes and the spring sleeve holes; springsleeves are mounted in the spring sleeve holes; and springs are mounted between the tightly-pushing block and the spring sleeves to enable the inclined surface I to abut against the inclined surfaceII. The detachable suspension clamp of the overhead conductor rail adopts the touch-type automatic detachment structure design, thereby realizing that the overhead conductor rail is touched when a flood prevention door falls, automatically detaching the slidably-detaching clamp from the suspension frame, and successfully closing the flood prevention door.