Mutually-tightened anti-loose bolt

The utility model relates to a mutually-tightened anti-loose bolt, which consists of a screw rod, an inner nut and an outer nut, wherein threads of the screw rod are positive and reverse threads; an internal thread of the inner nut is a positive thread; an internal thread of the outer nut is a reverse thread; 2 to 12 anti-slip grooves are formed on abutted surfaces of the inner nut and the outer nut and are in a structure which gradually rises in an anticlockwise mode. The anti-slip grooves are additionally formed on the abutted surfaces of the inner nut and the outer nut, when the inner nut is loosened due to impact, vibration or variable load, the inner nut and the outer nut mutually act in a loosening process, the outer nut is locked through the anti-slip grooves, and the inner nut is prevented from being loosened. The mutually-tightened anti-loose bolt is easy to manufacture and convenient to use, the nut of the bolt is effectively prevented from shedding off, and the connecting and fastening safety of electrical machinery equipment is improved.