Abstract: The present invention provides a detachable carrier support member for bicycle cargo racks includes a base plate, a frame rack set, and a plurality of clamping block sets. The base plate is fixedly joined to the bottom of a carrier, wherein the bottom of the base plate is attached to the frame rack set. Further, the base plate is secured on a fixed position by the plurality of clamping block sets that clamps and holds on to the support bar of the bicycle cargo rack. To attach the carrier support member to the bicycle cargo rack, the plurality of clamping block sets is inserted into a wedging groove disposed at two lateral frame racks of the frame rack set; whereby two control shafts brake and allow the user to quickly secure the carrier to and remove the carrier from the cargo rack.