The invention relates to a coaxial difference path device with check valve clacks. A valve clack connection shaft is composed of a first step, a second step and a third step, wherein the first step is used for connecting a movable end of a first-level valve clack; the second step is used for connecting a movable end of a second-level valve clack; the third step is used for connecting a center holder of the second-level valve clack and is positioned on the rear end of the center holder of the second-level valve clack; a return spring is arranged between the rear end of the center holder of the second-level valve clack and the center holder of the second-level valve clack; and the third step is located at the front end of the center holder of the second-level valve clack and is provided with a shaft section which is favourable for the center holder of the second-level valve clack to operate to the movable end of the second-level valve clack when the check valve is sealed and closed. The device effectively solves the problem that the other valve clack is prevented from sealing when one valve clack is blocked, and greatly improves the reliability of obstructing and sealing of the check valve.