Disclosed is a polarization maintaining connector. The PM connector includes an outer frame, a ferrule structure and an adjustment member. The outer frame forms a main structure of the PM connector. The ferrule structure is provided with a channel for a fiber core to pass through. The ferrule structure is at least partially disposed inside the outer frame and forms a slidable and rotatable connection with the outer frame. The adjustment member forms an axially slidable connection with the ferrule structure and is circumferentially non-rotatable relative to the ferrule structure. The adjustment member is relatively rotatable to the outer frame and has a rotating state and a holding state. The adjustment member keeps relatively rotatable to the outer frame when in the rotating state and keeps relatively secured to the outer frame when in the holding state.