The invention relates to a method for rapid measurement of a cable turning radius. The steps of the method are as follows: (1) a cable bending-degree measurement device is assembled; (2) three end points are set: a hinging end at which two upper pendulum rods are hinged at the end part of a measurement main rod is a B point and hinging ends of the two upper pendulum rods and respective lower pendulum rods thereof are an A point and a C point respectively; (3) measurement: the position of a slide block on the measurement main rod is adjusted according to be bending degree of the cable and the A,B and C points are closely attached at the inner side of the turn of the cable, a scale X on the measurement main rod at an elastic rope is read and the turning radius of the cable is obtained through a formula Y=L<2>/2X. The method for the rapid measurement of the cable turning radius is reasonable in design, convenient and rapid to apply, lower in cost, lower in demands on measurement process of inspection personnel and comparatively accurate.