The invention belongs to the technical field of coal mine gas treatment, and particularly relates to a low-position extraction roadway gas extraction method of a fully mechanized caving face. A low-position extraction roadway parallel to an air return roadway is arranged, and the low-position extraction roadway is located on one side of the return air roadway; the height of a caving zone is calculated according to lithology parameters so as to determine the arrangement layer of the low-position extraction roadway, and the arrangement layer of the low-position extraction roadway is located in the caving zone formed by covering a stratum on a mined working face. The low-position extraction roadway is mainly replaced with the technology that a special gas discharge roadway mode for treating upper corner gas is omitted. Goaf gas and the upper corner gas can be extracted; the arrangement layer is located in the caving zone range so that a channel for adjacent layer gas to move to the working face can be cut off after mining and pressure relief; when a highly collection tunnel cannot work, the adjacent layer gas is extracted under the action of negative pressure through the low-positionextraction roadway, threats of the adjacent layer gas to stoping are reduced, two purposes are achieved at the same time, and safety production of the high-gas fully mechanized caving face is effectively guaranteed.