Performance of giant magnetostrictive material (GMM) is introduced. Principle of work, basic structure and key techniques of giant magnetostrictive actuator (GMA) are analyzed. Its dynamic models of magneto-mechanical coupling are established. The structure and principle of the pneumatic servo valve and the micro pipe robot with new homemade GMM are presented. The experiment is carried out under typical working conditions. The experiment results show that the GMM pneumatic servo valve has wide pressure control characteristics, good linearity, and fast response speed. The movement principles of the GMM robot system are reliably feasible and its maximal moving speed is about 8 mm/s. It is preferable to the driving frequency of the robot within 100～300 Hz.