The invention discloses a combined anti-theft lock and a time alertor thereof. The technical scheme includes that an electronic lock is additionally arranged and installed in a lock body of a common mechanical lock so that the combined anti-theft lock is formed, and an anti-theft function and an alarming function at the time are achieved through match of the combined anti-theft lock and the time alertor. The combined anti-theft lock is integrally and structurally composed of a lock body (1), a marble spring bolt (2), a main spring bolt (3), a doorknob poking fork (4), a motor (5), a transmission worm wheel (6), a drive worm (7), a locating cam (8), a position-locking switch (9), a connecting bar (10), an electronic spring bolt (11), a key cylinder (12), a key cylinder fixing bolt (13), an auxiliary spring bolt (14), a counter lock poking fork (15) and a support bearing (16). When a theft invades, under the control of the time alertor, a mechanical spring bolt is locked through the electronic lock so that a door cannot be opened. The combined anti-theft lock and the time alertor can be widely applied to products such as emergency doors, security doors, safe boxes and safe cases.