Folding door

The invention belongs to the technical field of doors, in particular to a folding door. The folding door comprises a door frame and a door leaf, the door leaf is in pivot joint with the door frame, and the upper and lower ends of the opening and closing side of the door leaf are slidably connected with the upper and lower sides of the door frame. The door leaf comprises a plurality of modularized grilled doors in mutual hinge joint, and each modularized grilled door comprises a frame and a plurality of grille strips fixedly arranged on the frame at intervals. The folding door has the advantages that since the grille strips are arranged on the frame at intervals, the folding door plays a role in ventilation during sun shading in summer, and air conditioner refrigeration load in summer is reduced; in winter, sunshine can penetrate into a room through grilles to meet the needs of day lighting and direct-gain heating, and accordingly, the folding door well meets the needs of life.