A lifting device for an umbrella includes a base, a plurality of fixing seats secured on the base, a plurality of movable members each movably mounted in the respective fixing seat, a pressing module movably mounted on the base and pressing the movable members, a threaded rod mounted on the base and connected with the pressing module, and a drive handle connected with the threaded rod. The pressing module includes a driven rod and two pressing rods. Each of the pressing rods is provided with a straight pressing portion that is movable to press the respective movable member and at least one recessed release portion that is movable to receive the respective movable member. Thus, each of the movable members is rotatable freely so that the lifting device is moved on the ground easily.