This invention relates to the field of optical measurement equipment technology, specifically disclosing a mirror fixing device for optical measurement, comprising: a base, wherein a support rod is slidably connected to the base, and a fixing frame is fixedly connected to the support rod; a rotating shaft, rotatably connected to the fixing frame, a connecting frame being fixedly connected to the rotating shaft, and two support shafts being rotatably connected to the connecting frame, with a fixing shell fixedly connected between the two support shafts; two fixing columns, each fixedly connected to both sides of the fixing frame, each fixing column being slidably connected to a sliding rod, and a guide ring being fixedly connected between the two sliding rods; and a connecting shell, fixedly connected to one side of the fixing shell, with a ball-end rod slidably connected to the connecting shell. This invention eliminates the need for easily fatigued springs, employing a fully mechanical threaded sleeve and worm
gear transmission mechanism to achieve angle and direction adjustment. This mechanical structure eliminates the problem of elasticity attenuation and has strong resistance to vibration interference.