An ink-staining anti-theft cash box includes cash box mounted mainframe of bill acceptor, automatic vending machine or service kiosk and defining accommodation chamber, front opening and top mounting hole, ink cartridge including cartridge body mounted top mounting hole of mainframe, a plurality of ink holders accommodated cartridge body and actuator adapted for triggering ink holders, anti-theft security module with trigger unit mounted cash box, locking mechanism including control unit and operating unit operable drive control unit in locking or unlocking trigger unit. If cash box removed from mainframe by force without unlocking locking mechanism according normal unlocking procedure, trigger unit of anti-theft security module trigger actuator of ink cartridge, forcing respective ink holders to ink-stain storage bills in box body with unfading ink, causing bills lose their market value or transaction capabilities, deterring criminals to limit their criminal acts and enhancing security level of cash box.