A cash deposit and withdrawal machine and a core maintenance device thereof. The core maintenance device comprises a cabinet body (1), an upper core (2) provided on the upper portion of the cabinet body (1), and a lower core (3) provided on the lower portion of the cabinet body (1); the cabinet body (1) has a front panel and a rear panel provided opposite to the front panel; the upper portion of the inner side of the cabinet body (1) is provided with a first guiding assembly (13) for allowing the upper core (2) to slide, and the lower portion of the inner side of the cabinet body (1) is provided with a second guiding assembly (14) for allowing the lower core (3) to slide; the upper portion of the front panel is provided with a first opening for allowing the upper core (2) to pass therethrough, and the lower portion of the rear panel is provided with a second opening for allowing the lower core (3) to pass therethrough. The core maintenance device combines a front maintenance mode and a back maintenance mode, being applicable to scenarios such as counter ATMs, through-the-wall ATMs, and ATM islands. Moreover, the core maintenance device solves the problem of wasting time and labor force in a one-to-one serving mode, and is more secure.