The invention relates to a coring device for testing the strength of concrete according to a coring method. The device comprises a base (1), a vertical rod (2) arranged on the base (1), a rack (3) connected to the side surface of the vertical rod (2) in parallel, a first motor shell (4) sleeveing the periphery of the vertical rod (2) and the rack (3), a first rotating motor and a gear arranged inthe first motor shell (4), a second rotating motor (5) connected with the outer side wall of the first motor shell (4), and a drill bit (6) in transmission connected with the lower part of a rotatingshaft at the bottom of the second rotating motor (5). A strip-shaped first groove and a strip-shaped second groove are formed in the inner and outer peripheries of a drill bit body and a coring pipe of the drill bit, then water entering from a connector water inlet enters the drill bit body along the first groove to be cooled, and flows out from the second groove along with a concrete particle, the success rate of coring is increased, the testing time is shortened, and the detection cost is lowered.