The utility model provides an instrument stand fixing device with an anti-loosening structure, and relates to the technical field of instruments. The instrument stand fixing device with the anti-loosening structure comprises a base and an instrument stand, an anti-loosening fixing mechanism is arranged above the base, a push-out mechanism is arranged in the base, the anti-loosening fixing mechanism comprises a spring and a limiting block, and the limiting block is slidably connected to the surface of the inner wall of the base. The springs are fixedly installed on the two sides of the inner wall of the instrument base, and the instrument base is placed on the upper surface of the base. The instrument stand fixing device with the anti-loosening structure solves the problems that when an existing instrument stand fixing device is used, the fixing structure is prone to loosening, the position of an instrument stand deviates, the measuring precision of an instrument is affected, instrument faults can be possibly caused, and even safety accidents are caused. The beneficial effects that the instrument base can be prevented from loosening while the instrument base is fixed, and the influence on the use of the instrument is avoided are achieved.