The invention provides a prediction method for dynamic change of high-rank coal rock gas-phase permeability. The prediction method comprises the following steps: establishing relation between coal rock pore radius and gas pressure during the gas pressuring dropping process under in-situ reservoir stress and temperature conditions, establishing a prediction model for change of the coal rock gas-phase permeability, and predicting the dynamic change of the high-rank coal rock gas-phase permeability under the in-situ reservoir condition. According to the prediction method disclosed by the invention, the control factors for the change of the high-rank coal rock gas-phase permeability are change of the pore radius and temperature, the relation between the pore radius and the gas pressure is established to eliminate the difficulty for predicting the change of the pore radius, multiple coal rock permeability data under the in-situ reservoir stress and temperature conditions at different gas pressure are tested in a laboratory, and the model is used for fitting the dynamic change, so that the experimental operation is simple, convenient and feasible, and high in operability.