The invention disclose a combined driving sleeve of a drilling rig with a reliably fixed draw key, which comprises: a driving sleeve body (1), a draw key (2), a fixed stopper block (6), a movable stopper block (7), and bolts (8), the fixed stopper block (6) is fixed at one end of a groove of the driving sleeve body (1), while the movable stopper block (7) is fixed at the other end of the groove of the driving sleeve body (1) by means of a bolt (8), and the draw key (2) is fixed into the groove of the driving sleeve body (1) by means of the fixed stopper block (6) and the movable stopper block (7). The advantages thereof are: the draw key is reliably fixed and will not easily come loose; the method of mounting the draw key of the driving sleeve is simple and manufacturing costs are low; the operating space for replacing the draw key is large, and labor intensity is low; and the draw key is longitudinally symmetrical and can be inverted and interchanged.
