Method for predicting coal seam gas parameters

The invention provides a method for predicting coal seam gas parameters. The method comprises the following steps of 1) constructing a coal molecular model according to coal sample components and structure information obtained by an experiment and optimizing the coal molecular model; 2) based on molecular simulation, adding a corresponding number of water molecules to a single coal molecule according to coal sample moisture, then adsorbing methane molecules, converting an adsorption result unit into a consistent statistical magnitude, and fitting to obtain a coal adsorption gas isotherm of different moisture and a functional expression thereof; 3) measuring coal seam pressure, and converting according to an ash content of a coal sample based on the isotherm map to obtain the coal seam gascontent; and 4) integrating the isotherm function expression to obtain a gas extraction quantity. The method for predicting the coal seam gas parameters has great application prospects in predicting the coal seam gas content