Cipher device and bicycle child seat anti-theft coded lock assembly

The invention discloses a cipher device, which comprises a bottom supporter, a tooth-shaped wheel group and a shaft rod, wherein the wheel group is connected outside the shaft rod and rotates relative to the shaft rod, the shaft rod is fixedly connected with the bottom supporter, a long strip is clamped and connected with the wheel group, a lock bolt sliding on the bottom supporter is limited between the long strip and the position limiting block, and one end, near the position limiting block, of the lock bolt is the slope-shaped end, and realizes the matched action with the position limiting block arranged on a lock hook press button; when the cipher setting is incorrect, the tight locking is realized; the unlocking is realized when the cipher is correct. The invention also discloses a bicycle child seat anti-theft coded lock assembly, which comprises the cipher device, a U-shaped bent pipe and a support casing. A child seat is fixed with one end of the anti-theft lock provided by the invention, the other end is connected with the cipher device, the fast dismounting of the child seat can also be realized under the condition that the cipher device or the coded lock is unlocked or locked, in addition, the structure is simple, and the operation is convenient. The cipher device is suitable for being used for the coded lock, and is particularly applicable to the coded lock for a bicycle child seat.