Abstract: To measure the closed orbit distortion of the beam in Lanzhou Heavy Ion accelerator Cooling Storage Ring main ring (CSRm) and perform closed orbit correction, the authors have developed a closed orbit correction system. It consists of an orbit measure system, a closed orbit control system and a corrector magnet system. The orbit measure system realizes real-time monitoring of the beam orbit; the closed orbit control system reads the orbit information, performs the closed orbit correction calculation, and transmits the calculated correction value to the corrector magnet system; the corrector magnet system changes the intensity of the corrector magnet by changing the settings of the corrector power supply, thereby realizing the adjustment of the beam orbit. The simulation test show that the maximum distortion in the horizontal direction is reduced from 3.37 mm to 0.39 mm, and the maximum distortion in the vertical direction is reduced from 4.21 mm to 0.31 mm. The system can measure the response matrix and correct the beam orbit automatically. It meets the design requirements.