Abstract: The present invention aims at improving the shock resistance of a block without lowering the power transmission property or the wear resistance of a belt while suppressing the separation of the contact portion off of the reinforcing member. A high-load drive V-belt B includes: at least one tension band 10 extending in an endless loop; and a plurality of blocks 20 engaged and secured to the tension band 10 at a predetermined pitch in a belt length direction of the tension band 10, wherein the plurality of blocks 20 are each formed by a reinforcing member 27 and a resin on both sides of the reinforcing member 27 in a belt width direction, and each include a contact portion 28 having a contact surface 30 to be in contact with a pulley, and a thickness w of the contact portion 28 in a direction perpendicular to the contact surface 30 is set to 1.0 mm or more and 1.8 mm or less.