Disclosed is a full-width seal device, the outer part of which comprises a paper inlet, a paper outlet and a housing, and the inner part of which comprises a component moving along the x-axis, a component moving along the y-axis and a seal mechanism, wherein the component moving along the x-axis is used for detecting whether paper has entered the paper inlet and having detected that paper has entered the paper inlet, driving the paper to move along the x-axis; having detected that the paper has moved to a pre-set position on the x-axis, the component moving along the y-axis is used for driving the seal mechanism to move along the y-axis; and after the paper has moved to a pre-set position on the y-axis, the seal mechanism is used for executing a seal operation.