The utility model discloses a novel monkey wrench quickly adjustable in opening. The novel monkey wrench quickly adjustable in opening comprises a handle, a wrench movable head and a wrench fixed head, wherein a ratchet is arranged at the bottom of the wrench movable head, a through groove is formed in the handle at the lower portion of the wrench fixed head, a dial wheel is transversely arranged in the through groove, convex teeth on the dial wheel are meshed with the ratchet on the wrench movable head, a dial wheel supporting shaft penetrates through the center of the dial wheel, two ends of the dial wheel supporting shaft are arranged in the groove formed in the handle on two sides of the through groove, the dial wheel supporting shaft can vertically slide in the groove, springs are vertically arranged at the bottoms of the two ends of the dial wheel supporting shaft, and the tail ends of the springs are fixed to the bottom of the groove. Compared with the prior art, the opening size can be rapidly and easily adjusted, the adjustment time is effectively shortened, physical output is reduced, and working efficiency is improved. In addition, the novel monkey wrench can be adjusted like a common monkey wrench and is simple and easy to use, simple in structure and easy to popularize, learning cost is reduced, the working efficiency is improved while the labor intensity is reduced.