The invention discloses a driver's cab activation interlocking circuit and method, and a train. The interlocking circuit comprises two interlocking units. Each interlocking unit comprises a first relay and a second relay. One ends of coils of the first relays are grounded, and the other ends of the coils of the first relays are connected with first contacts of the first relays and contacts of thesecond relays; the first contacts of the first relays and the contacts of the second relays are connected in parallel and then connected to a driver key of one driver's cab; one ends of coils of the second relays are grounded, and the other ends of the coils of the second relays are connected with second contacts of the first relays; the second contacts of the first relays and the driver key are connected to a power supply; connections are arranged between the second contacts of the first relays and the coils of the second relays; and connections of the two interlocking units are connected. According to the invention, the logic interlocking function of an activation terminal is fulfilled from the hard line of the train, and the conflict judgment problem of train activation is solved from the hard line.