The invention relates to a method for coal and gas simultaneous extraction based on one bottom pumping lane for three purposes. The method comprises the following steps of according to the geologicaloccurrence conditions of a close-distance coal seam group, performing drilling towards a top plate of an upper adjacent coal seam and a bottom plate of a lower adjacent coal seam at an air return laneof a present coal seam working face, detecting the interval between the upper adjacent coal seam and a present coal seam and the interval between the lower adjacent coal seam and the present coal seam, taking a coal sample, and testing and analyzing the physical and mechanical parameters of each coal stratum; determining the construction position of the bottom pumping lane in the lower adjacent coal seam; when gas in the lower adjacent coal seam is required to be pre-extracted, according to the coal seam thickness and inclination angle of the lower adjacent coal seam, constructing a bedding drilled hole in the bottom pumping lane, sealing the hole and connecting a high-negative-pressure extraction system; when gas in a high-position fracture zone is required to be extracted only, constructing a high-position drilled hole in the bottom pumping lane according to the physical and mechanical parameters of an overlying coal and rock mass, enabling the final hole position to fall in the fracture zone of the present coal seam, sealing the hole, and connecting the high-negative-pressure extraction system; and when gas in an existing goaf is required to be extracted, constructing a connecting lane in the bottom pumping lane towards the air return lane of the present coal seam working face, building a fire dam, inserting an extraction pipeline, and connecting the high-negative-pressureextraction system.