The invention discloses ground zero-gravity separation test equipment for a large spacecraft. The ground zero-gravity separation test equipment comprises a test bracket, pulley assemblies, a buffer mechanism, a locking mechanism, a connecting rope, a weight balancing and lifting mechanism, a tension recorder and a test sling, wherein the test bracket is a cubic frame structure; a pulley mechanism I is arranged on one side surface of a frame in a suspension manner; the test sling is connected to the lower end of the connecting rope, and the weight balancing and lifting mechanism is connected to the other end, going around a pulley mechanism II, of the connecting rope; the two pulley assemblies are respectively arranged on a top cross beam of the frame structure so as to support the connecting rope which goes around the pulley assemblies; the buffer mechanism comprises a buffer and a buffering stop block; and the connecting rope drives the buffering stop block to move together at a uniform speed until the buffering stop block impacts the buffer to enable the kinetic energy to be dissipated.