A folding bed is provided, which includes a bed sheet, a first lateral supporting rod connected to a first edge of the bed sheet and a second side supporting rod connected to a second edge of the bed sheet. The folding bed further includes a first L-shaped supporting rod having a first end articulated to the first side supporting rod, a second L-shaped support rod having a first end articulated to the second side supporting rod, a gear connected to a second end of the first L-shaped supporting rod, and a gear locking member connected to a second end of the second L-shaped supporting rod. The gear locking member is provided with teeth which are rotatable in only one direction with respect to teeth of the gear. The folding bed is has a small size after being folded, is convenient to assemble and is easy to fold.