The invention discloses an automatic release device and a washing machine. The automatic release device comprises a drawable detergent box installed in a water box; the detergent box is provided witha press rod, one end of the press rod is in plug connection, and the other end of the press rod is provided with a lock tongue which is convex outwards, so that the lock tongue is enabled to shrink towards the interior of the detergent box after a user presses the press rod, and the lock tongue is further unlocked. By installing the press rod which can be elastically deformed under the action of an external force on the detergent box, the user can press the press rod so as to enable the lock tongue on the press rod to contract and move, so that the aim of separating the lock tongue from the water box or locking for limiting can be achieved. Furthermore, the automatic release device is simple in structure and remarkable in effect, thus being suitable for popularization and use.