In this paper, the constitution of an exhausted-air reclaiming system for pneumatic cylinders is studied. The effect of the system on the cylinder velocity characteristics and the control method are also researched. Experimental results show that attachment of a reclaiming device would not cause bad influence on the velocity stability if the switch point could be properly controlled. Experiments also indicate that the switch control differential pressure DPsw varies with Pc in receiver and the supply pressure Ps and affect the velocity stability of cylinders. Therefore for reclaiming more energy and making less influence on the cylinder velocity characteristics, the suitable switching-point and the value of DPsw are also tested and suggested.