Rotating packedoeds (RPBs) using centrifugal force to intensify mass transfer are HIGEE units with high performance [1].The zigzag rotating bed (RZB) is a new type of HIGEE unit [2].The rotor of RZB consists of stationary disc and rotating disc,forming zigzag channels for liquid-gas flow and mass transfer.The understanding of the three-dimensional gas velocity in the region of zigzag channel is essential for the design of the RZB rotor[3].The experiments were carried on in a RZB rotor of 490 mm-diameter with air system.