Abstract: The physical model of liquid film diffusion was proposed on the basis of the influence of fluid field condition on liquid film diffusion. Different fluid fields and different liquid film thicknesses may lead to different mass transfer resistance, thus influencing the mass transfer effectiveness. Besides, liquid film diffusing control equation was modified by introducing fluid field effect coefficient Z and the new definition of fluid speed. In addition, the rationality of the modified model was proved by the adsorption experiment of calcium ionon 13X zeolite. The result showed that, the adsorption efficiency has relation with fluid field distribution. With the increasing of the concentration of Ca²⁺,the mass transfer speed become rapid, and the influence of fluid field distribution become little. This may attribute to the influence of mass transfer drive force which becomes much more important than liquid film resistance.