The invention discloses a mechanical automatic reset device for interlocking a three-station mechanism, comprising a top plate (3) and an operating gear (2). The top plate (3) is connected with a first driven cam assembly (13), a second driven cam assembly (6), a first three-link mechanism (22), a second three-link mechanism (23), a driven camshaft of a driven unlocking cam (16), and an driving camshaft of a driving unlocking cam (17), The driven camshaft is connected with the driven unlocking cam (16). The driving camshaft is connected with the driving unlocking cam (17). The operating gear (2) is connected with a first driving cam assembly (11) and a second driving cam assembly (21). The device can prevent the three-station mechanism from causing equipment damage or even personal safetyaccidents because of directly crossing a mechanical breakpoint position to directly reach another position due to any factor, and is compact in structure and high in integration.