The clean compressed air is taken as power transmission medium in pneumatic clamping devices, and when cutting after clamping the workpiece, the energy are not consumed any more. So it can be said that it is a green clamping technology. However, a low pressure of pneumatic driving makes a lot of pneumatic fixtures too bulky in size.A new innovation design idea of clamping mechanism based on pneumatic muscle and the eternallever-toggle force amplifier is described in this paper, in which the pneumatic muscle is instead of traditional rigid cylinder. The pneumatic muscle has some features such as extremely simple structure, good flexibility, the big ratio of output force and diameter/weight, etc. Thus, this device can get much greater clamping force on the condition of reducing the size and weight of the structure definitely. In addition, using two pneumatic muscles alternately, it can enable the time of processing a workpiece to overlap with the time of unloading another workpiece, and which can improve the production efficiency significantly.