The functions of hydromechanics and volumetric mass transfer coefficient K(X)a of cross flow packed tower were studied by setting baffle plates. The influence of plate spacing on the pressure drop, height of the mass transfer unit, and mass transfer characteristics were investigated in an ordinary packed tower and a cross flow packed tower. The pressure drop increased with a rise in the flow rate of gas and liquid, and an excessive pressure drop caused flooding in the cross flow packed tower. The height of the mass transfer unit increased with a decrease in the gas flow when H/D = 0.8-1.2, while increased with the increase of the gas flow when H/D = 0.6. In the ordinary packed tower and the cross flow packed tower, K(X)a increased with a rise of liquid flow. The influence of gas flow on K(X)a was negligible in the ordinary packed tower, however, in the cross flow packed tower the K(X)a gradually increased with a rise in the gas flow rate. The effect of mass transfer was optimal at H/D = 0.8. In addition, using STATISTICA software, the corresponding K(X)a correlations were proposed and discussed.