The present invention relates to a mono-type gate valve system in which a sealing member is formed to have a stepped shape so that a path can be opened and closed by means of only a raising operation of a door. The mono-type gate valve system may comprise: a valve housing that includes a path formed in at least one portion thereof and a door replacement region formed in another portion thereof, the path having a first lower surface and a second lower surface; a mono-type door in which a first sealing member corresponding to the first lower surface and the second lower surface of the path is installed to enable the path to be opened and closed; an ascending/descending stand that supports the door; a raising/lowering shaft for raising and lowering the ascending/descending stand; and a movement device for door replacement, which moves the door from a first position to a second position so that the door can open and close the path when raised and lowered at the first position and can be moved to the door replacement region when raised and lowered at the second position.