The invention discloses a supporting device for nut rotation and screw movement mounting of an underneath type sink. The technical scheme is as follows: the supporting device comprises a square supporting frame and a rack, wherein the upper end surface of the square supporting frame is fit with lower surfaces of peripheral edges of the sink, a plurality of pressing blocks are evenly distributed on the lower end surface of the square supporting frame, the rack is mounted on a vertical board of a cabinet, an adjusting nut is arranged at the lower end of each pressing block, the lower end of each adjusting nut is in threaded connection with a stud, and an adjusting head for a user to rotate the adjusting nut conveniently is arranged outside the lower end of each adjusting nut. With the adoption of the scheme, the supporting device for mounting of the underneath type sink has pressing and locking functions.