The excitation energy acquired by the goal molecules in microwave field was theoretically analyzed from the interaction between goal molecules and microwave field.The effective diffusion equation of the goal molecules in bulk material in microwave field was deduced on the basis of the theory of liquid lattice model

and the mechanism of goal component diffusion enhanced by microwave field was analyzed.The results indicated that the bulk material porosity increased by microwave field and non-calorific energy acquired by goal molecules were the main reasons for the goal molecules diffusion enhanced by microwave field

and the general characteristics of the extraction process enhanced by microwave field were revealed.A kinetic model of goal component diffusion in microwave field was further established by simplifying the effective diffusion equation.The fitting of experimental data showed that theoretical curves of different parameters of the same kinetic equation were in agreement with different experiment results respectively，and all fitting correlation coefficients were above 0.96.The experimental data fitted under different conditions satisfied the same kinetic law and the kinetic model established was adaptive and appropriate to some degree.