A slide automatic-closing buffer assembly comprises a base, a sliding block, at least one elastic element and a bump. The base is disposed at an end of an outer rail, and the bump is disposed at an end of an inner rail, and the sliding block is movably installed in a containing space of the base, and the elastic element is coupled between the base and the sliding block, and the present invention is characterized in that the containing space has at least one buffer rail, and the sliding block has a buffer wheel corresponding to the buffer to rail slow down the sliding block and buffer the impact produced when the elastic element is pulled back to achieve the required automatic returning, closing and buffering effects required by a slide.