The invention discloses a universal instrument. The universal instrument comprises a box body and a cover body, wherein an observation opening, a connecting sliding chute, supporting rods and a wiring opening are arranged on the box body; the observation opening is formed in the front end of the box body; the connecting sliding chute is mounted and fixed to the side surface of the box body through bolts; a connecting sliding block is arranged in the connecting sliding chute in a penetrating manner; through holes are formed in corners of the connecting sliding block; one ends of the supporting rods are connected on the inner two sides of the box body through a rotating shaft; the other ends of the supporting rods are connected on the two sides of the front end of the instrument through the rotating shaft; the instrument is placed in the box body; the wiring opening is formed in the bottom of the back end of the box body; the cover body is connected on the box body through a hinge; push-pull rods are connected on the inner two sides of the cover body through the rotating shaft; and the other ends of the push-pull rods are connected on the two sides of the back end of the instrument through the rotating shaft. According to the universal instrument, structure is simple, maintenance is convenient, and waterproofness and dust prevention property of the instrument are effectively improved.