The invention discloses a concealed synchronous pin tumbler lock. The pin tumbler lock mainly comprises a key and a lock cylinder. The key mainly comprises a key handle shell, a reset spring, a reset spring strip, a baffle locking piece, a baffle locking gear, a cylindrical shaft, a baffle motion guiding piece, a baffle and a tooth pattern part. The lock cylinder mainly comprises a lock cylinder shell, a compensation block, a spring strip, a shelter, a lock cylinder rotor, a rightward pin tumbler, a leftward pin tumbler, a lock cylinder bottom plate, a clamping spring and a spring. According to the lock cylinder in the pin tumbler lock, when the lock is opened with the key, the interior of the lock cylinder must be totally separated from the outside, and therefore the possibility of technical unlocking does not exist. Because the pin tumblers will not touch the inner wall of the lock cylinder shell, it is impossible that the actual positions of the pin tumblers are sensed by poking the pin tumblers, and therefore technical unlocking cannot be achieved through the attempt to poke the pin tumblers to the unlocking positions. The position, allowing the lock to be opened, of each pin tumbler is unique, and thus pin tumbler skip unlocking can be avoided. The shapes and the arrangement mode of the pin tumblers are changed, and thus the secret key amount of the lock is greatly increased. The technical requirement for manufacturing of the lock is not substantially raised, and thus the production cost will not be increased substantially.