The development of low afterglow cesium iodide crystal is very important for the application of cesium iodide crystal in modern security check and medical CT equipment. In this paper, low afterglow cesium iodide crystals by co-doping were grown by an improved Bridgman method, with purified raw materials in which impurities influencing crystal afterglow were removed, the scintillation properties of the crystal were studied. The results show that the afterglow value of the crystal obtained by this method is about 0.31%@50 ms, which is much lower than that of conventional cesium iodide crystal.