Abstract: It is difficult that measuring coal-seam permeability and methane pressure and measurement accuracy is low. This paper constructed theory and method of determining coal-seam permeability and methane pressure on the basis of methane racial flow principle. On-the-spot measurement with different bore-hole diameters and different flow was finished in Wuyang Colliery. Results showed that the influence of bore-hole diameter on calculation value of coal-seam permeability and methane pressure was small, but that of methane flow monitoring time was obvious. Flow data after 5 days of bore-hole construction should be selected for linear regression analysis to reduce error. Relative error of calculation value and measurement value was small, which showed that this method could meet the requirement of basic methane parameter in methane prediction and prevention.