A silent key switch includes a base body, a static contact, a dynamic contact, a movable plate, a first balancing stand, a second balancing stand, and a keycap. The movable plate includes a silencer body arranged on the head of the movable plate, a U-shaped groove provided on the rear part of the movable plate, and a first slot provided adjacent to the silencer body; one end of the movable plate where the silencer body is located is abutted against the dynamic contact and the static contact; the first balancing stand and the second balancing stand intersect with each other and are pin jointed together in a superimposed way.