The invention discloses a while-drilling measuring device for mashgas desorption characteristic parameters of drilling coal scraps, wherein the device comprises a double-wall drill rod, an outer pipeand a drill bit, and the front end of the outer pipe is connected with the drill bit; an installation chamber is arranged between the outer pipe and the drill bit, a measuring device and an in-pipe piston sealing device are arranged in the installation chamber, and the measuring device is located at the front side of the in-pipe piston sealing device; the double-wall drill rod comprises the double-wall drill rod outer pipe; the double-wall drill rod outer pipe is internally sleeved with a double-wall drill rod inner pipe in clearance fit with the double-wall drill rod outer pipe, and an expansion clearance is formed between the double-wall drill rod outer pipe and the double-wall drill rod inner pipe; the double-wall drill rod inner pipe passes through a drill rod connector and is airtightly connected with the back end of the piston outer pipe, the double-wall drill rod outer pipe is fixedly connected with the drill rod connector, and the double-wall drill rod outer pipe is externallysleeved with a drilling sealed separation device. The while-drilling measuring device for the mashgas desorption characteristic parameters of the drilling coal scraps can measure the coal seam mashgasparameters without withdrawing a drill during drilling, thereby improving the continuity of the measuring work and the drilling work.