The gas phase pressure drop in the cross-flow rotating packed bed（RPB）is an important factor in its application and design. The gas phase pressure drop was investigated with air-water system.The total pressure drop was divided into four stages according to gas flow path—gas inlet pressure drop，rotating packed bed pressure drop，transformation of kinetic energy in gas collector and gas outlet pressure drop. The total pressure drop was measured and correlated with experimental values. The simulation result from the model coincide with experimental measurements. The experimental data showed that the total pressure drop of the cross-flow RPB was influenced by rotating speed，gas flow rate and liquid flow rate. The total pressure drop decreased first and then increased with increasing gas flow rate in the case of low gas flow rate and high rotating speed.In other cases the total pressure drop increased with increasing gas flow rate.The total pressure drop decreased with increasing rotating speed

and the change was obvious at a low gas flow rate.The total pressure drop increased with increasing liquid flow rate

and the change was obvious at a low rotating speed.