Micro pneumatic servo valve

The utility model relates to a micro pneumatic servo valve which belongs to pneumatic servo valves. A pipe joint I is fixedly connected with one end of a valve body, an end cover is fixedly connected with the valve body, a biasing spring is positioned inside the valve body, a pipe joint II is fixedly connected with the other end of the valve body, a cone valve spool is positioned inside the valve body, the tip end of the cone valve spool is positioned inside the pipe joint II, an insulator is positioned between the biasing spring and the cone valve spool, and a biological metal fiber has one end thereof connected with the end cover and the other end thereof connected with the cone valve spool via a cylindrical pin. Because the biological metal fiber can generate deformation at a low temperature due to the good bidirectional shape memory function in the shape recovery range, the biasing force needs not to be applied when a driving device is constructed from the biological metal fiber. The micro pneumatic servo valve can be combined with the spring to obtain an opposing force in case of retraction. The micro pneumatic servo valve has simple foundation design, miniaturized and simplified structure, and easy implementation.