The invention discloses a combined counterweight device and a crane using the same and aims to solve a problem that the prior counterweight device cannot move backwards and forwards. The combined counterweight device of the invention comprises a counterweight body, two horizontal slide rails, a counterweight bracket, two vertical oil cylinders and two horizontal oil cylinders, wherein the vertical oil cylinders are fixed on the counterweight bracket through the bodies of the two vertical oil cylinders, and the counterweight bracket can slide backwards and forwards along the horizontal slide rails fixedly arranged on two sides of the tail part of a turntable under the action of the two horizontal oil cylinders. The key design points of the combined counterweight device and the crane using the same include: the counterweight body can move backwards and forwards to effectively improve the length of the big arm and the vehicle stability under a large amplitude working condition of the crane and to reduce the vehicle length to impact the structure of the crane respectively; and at the same time, the crane has a relatively small radius when driving on a curve, so the rideability of the crane is greatly improved.