A high-strength one-touch rebar coupler according to the present invention comprises: a coupler body having a hollow portion formed in the longitudinal direction, the coupler body being formed in a helical shape so as to provide the inner peripheral surface of the hollow portion with a rebar fastening force in the circumferential direction, and the coupler body comprising a first guide helix coupling portion, which has first guide sloping portions that slope from the center portion of the hollow portion towards the outside of one side thereof, and a second guide helix coupling portion, which has second guide sloping portions that slope from the center portion of the hollow portion towards the outside of the other side thereof; a first fastening unit screw-coupled to the first guide helix coupling portion of the coupler body and inserted into one side of the hollow portion, the first fastening unit comprising a plurality of first fastening members, which are coupled to the first guide sloping portions so as to be able to slide, respectively, each of the first fastening members having a first fastening helix coupling portion, which has a first fastening sloping portion, provided on the outer peripheral surface thereof and having a first grasping portion, which grasps the outer peripheral surface of a rebar for connection, provided on the inner peripheral surface thereof such that, when tensile forces act on coupled rebars, the first fastening members move in the opposite direction of the radial direction and thereby provide the rebars with fastening forces; and a second fastening unit screw-coupled to the second guide helix coupling portion of the coupler body and inserted into one side of the hollow portion, the second fastening unit comprising a plurality of second fastening members, which are coupled to the second guide sloping portions so as to be able to slide, respectively, each of the second fastening members having a second fastening helix coupling portion, which has a second fastening sloping portion, provided on the outer peripheral surface thereof and having a second grasping portion, which grasps the outer peripheral surface of a rebar for connection, provided on the inner peripheral surface thereof such that, when tensile forces act on coupled rebars, the second fastening members move in the radial direction and thereby provide the rebars with fastening forces.