A mechanical end-effector changer, comprising a base frame; a damper mounted in said base frame; a first connection unit comprising a first holder base and a post, said first holder base being positioned on said damper, said post comprising an engagement hole; and a second connection unit comprising a second holder base, a first movable member, a first elastic member, a second movable member, a second elastic member, a third movable member, a third elastic member, a fourth movable member and a fourth elastic member, said second holder base comprising a first chamber, a second chamber, a first through hole and a second through hole, said second holder base being detachably coupled to said post by means of said first chamber, said first through hole being disposed in communication between said first chamber and said second chamber, said second through hole being disposed in communication between said second chamber and an outer perimeter of said second holder base, said first movable member being mounted in said second chamber and detachably abutted against said first holder base, said first elastic member being mounted in said second chamber and stopped against said first movable member, said second movable member being mounted in said first through hole and detachably engaged in said engagement hole of said post, said second elastic member being mounted in said first through hole and stopped against said second movable member, said third movable member being mounted in said first through hole and detachably connected to said first movable member, said third elastic member being mounted in said first through hole and stopped between said second movable member and said third movable member, said fourth movable member being mounted in said second through hole and squeezable by said base frame to push said first movable member, said fourth elastic member being mounted in said second through hole and adapted for moving said fourth movable member toward said outer perimeter of said second holder base. a base frame; a damper mounted in said base frame; a first connection unit comprising a first holder base and a post, said first holder base being positioned on said damper, said post comprising an engagement hole; and a second connection unit comprising a second holder base, a first movable member, a first elastic member, a second movable member, a second elastic member, a third movable member, a third elastic member, a fourth movable member and a fourth elastic member, said second holder base comprising a first chamber, a second chamber, a first through hole and a second through hole, said second holder base being detachably coupled to said post by means of said first chamber, said first through hole being disposed in communication between said first chamber and said second chamber, said second through hole being disposed in communication between said second chamber and an outer perimeter of said second holder base, said first movable member being mounted in said second chamber and detachably abutted against said first holder base, said first elastic member being mounted in said second chamber and stopped against said first movable member, said second movable member being mounted in said first through hole and detachably engaged in said engagement hole of said post, said second elastic member being mounted in said first through hole and stopped against said second movable member, said third movable member being mounted in said first through hole and detachably connected to said first movable member, said third elastic member being mounted in said first through hole and stopped between said second movable member and said third movable member, said fourth movable member being mounted in said second through hole and squeezable by said base frame to push said first movable member, said fourth elastic member being mounted in said second through hole and adapted for moving said fourth movable member toward said outer perimeter of said second holder base.