Abstract:As compared with the common fixed degree of freedom mechanism, the metamorphic mechanism has special properties. One kind of self-adaption four-constructional element metamorphic master manipulator was designed, which was driven by gas. This manipulator was simplified and had only three fingers, which were driven by a pneumatic cylinder, and each finger had two revolute joints. In order to control the cylinder pressure, the part of each finger which would be used to hold object was lined with silica gel and force sensor, so that the holding force could be adjusted in a certain range. This manipulator was a flexible actuator to a certainty. This actuator was combined of the working principle of metamorphic mechanism with the technology of the gas-flexible-drive, which was one kind of pneumatic self-adaption flexible master manipulator based on four-constructional element metamorphic mechanism. The structure principle of the master manipulator was described, and it was analyzed in kinematics. The analysis shows that the manipulator has ability of self-adaption, which is suitable to use in catching fragile glass bottles, the human massage actuator and others.