The invention provides a method and device for determining a transporting capability parameter of rock mass. The method comprises the steps of obtaining an included angle between to-be-tested rock mass and a horizontal plane and taking the included angle as a stratigraphic dip; obtaining the permeability of the to-be-tested rock mass, wherein the permeability comprises horizontal permeability and vertical permeability; and calculating the transporting capability parameter of the to-be-tested rock mass according to the horizontal permeability, the vertical permeability and the stratigraphic dip. According to the method and the device, the transporting capability parameter of the to-be-tested rock mass is calculated through the angle between the to-be-tested rock mass and the horizontal plane and the permeability of the to-be-tested rock mass, and the target of quantitative evaluation of the transporting capability of the to-be-tested rock mass is achieved, so that the distribution law of an oil-gas reservoir can be better predicted according to the transporting capability parameter and the geological prospecting risk is reduced.