The invention provides a miniature friction-less multifunctional valve, comprising a valve body, a valve cover, a valve base, a sealing ring, a pressing plate, a valve pin, a sleeve, a cam, a valve rod, a seal housing, a pressing cover and an O-shaped ring, characterized in that : the valve base is screwed into the valve body on the left end, on the joint of them, a seam-cross screw is mounted, the valve pin is supported in the channel between the valve body and valve cover by the sleeve, between the inner chamber steps of the valve body and the valve pin convex bench, a spring is arranged, the spring is positioned by a guide bar, the guided bar is inserted into the relative holes of valve body and valve cover through the valve pin convex bench, the valve bar is fixed to the cam by bolts or welding. The invention can realize reliable switching, and also can be used for adjusting, and there is no friction on between the sealing faces, which prolongs the useful life.