The invention discloses a glue spraying mechanism of a hot melting compounding machine. The mechanism comprises a first supporting frame, wherein a conveying belt is mounted at the upper end of the first supporting frame; a hot melting compounding machine is mounted on the conveying belt; a glue spraying head is arranged at the front end of the hot melting compounding machine; second supporting frames are arranged on the two sides of the bottom of the hot melting compounding machine; edge conveying belts are installed on the second supporting frames; the edge conveying belts are arranged on the two sides of the conveying belt; glue removing chambers are arranged at the bottom of the second supporting frames; glue removing scrapers are arranged in inner cavities of the glue removing chambers; a driving roller is arranged at the bottom of the glue removing chambers; and a first driving motor is installed on one side of the driving roller. Because the edge conveying belts are arranged onthe two sides of the conveying belt, redundant glue can be sprayed to the edge conveying belts, and scraped by the glue removing scrapers to achieve automatic glue removing, glue accumulation is prevented, normal use is achieved, glue removing is convenient and rapid, the working efficiency is improved, and the labor intensity is reduced.