The invention relates to a coal sample sampling method and device. The method includes the steps of obtaining the depth of a coal body plastic area, drilling to take a round coal core in a coal body elastic area according to the requirements, drilling to take test pieces in the radial direction of the coal core, and then grinding two ends of the test pieces to be flat to form standard test pieces. The sampling device comprises a positioning device and a coring device; the positioning device comprises a marking structure, an angle testing probe, a receiving device, a centering structure, an extension rod and a signal transmission line. The taken coal sample can be guaranteed to be in the coal body elastic area, the coal core can be reset in the initial position in the coal body, and the standard test pieces can be reset in the initial form in the coal body; the testing data of physico-mechanical properties can be guaranteed to be reasonable and accurate and represent coal body real data.