Hidden telescopic lock

The utility model relates to a hidden type telescopic lock which comprises a lock box, a control groove is formed in the lock box, a control assembly is arranged in the lock box, a spring bolt assembly matched with the control assembly is arranged in the lock box, and the control assembly comprises a switch base fixedly installed on the inner bottom wall of the control groove. The hidden telescopic lock needs to be matched with a traditional lock for use, when the hidden telescopic lock is normally opened, a key unlocks the surface lock, then a round bar is inserted into an insertion cylinder, then pressing is carried out, a limiting plate, a conical block and a lock block are driven to move deeply till the lock block makes contact with a switch base, a controller can control a telescopic rod to contract, and therefore the telescopic rod can contract; if someone wants to damage the surface lock to open the drawer, after the surface lock is damaged, the round bar matched with the inserting cylinder falls off,