Abstract: The pressure recovery system is an important part of Chemical Oxygen-Iodine Laser(COIL). Adopting cryosorption vacuum system as the pressure recovery system of COIL, the pressure recovery capability of cryosorption vacuum system is determined directly by the performance of adsorption bed. In this paper, the heat transfer efficiency of the adsorption bed with different structure was studied with theoretic and experimental approaches. It is found that the flow state and pattern of liquid nitrogen in pipe have great influences on the heat transfer. After structure improvement, the heat transfer coefficient between adsorption bed and liquid nitrogen has been increased by 2.2 times. It is proved that the improvement in the adsorption bed structure has enhanced the heat transfer effect of adsorp