The invention relates to a heavy load universal connecting device for connecting a drilling tool and a drill rod, which consists of a central pipe 1, a middle bush 2, springs 3, small shafts 4, a shell 5, ball head cylindrical pins 6, a wear-resistant bush 7, an upper transition disc 8, a lower transition disc 9, a lower ball surface 10, an upper ball surface 11, bellevill springs 12 and a supporting disc 13, wherein the central pipe is arranged on the middle part of the labyrinth type shell, and the upper end of the central pipe is additionally provided with the middle bush; six small shafts are uniformly distributed along the circumference of the central pipe, each small shaft is arranged in a round pipe which is specifically arranged in the shell, and the tail of the small shaft is additionally provided with the spring; the lower end of the central pipe is provided with the lower ball surface in a pressing mode, and the upper ball surface is arranged corresponding to the lower ball surface and connected with the supporting disc in a floating mode through a plurality of the bellevill springs; the supporting disc is fixed with the shell through a bolt; the lower end of the central pipe is a hexahedron which supports the lower transition disc, and the lower transition disc is matched with the ball surface of the wear-resistant bush 7 embedded in the upper transition disc to support the upper transition disc through the two symmetrical ball head cylindrical pins; and the upper transition disc supports the shell through the two ball head cylindrical pins, and the two ball head cylindrical pins are arranged reversely at an angle of 90 degrees.