a fire door lock includes a base assembly including first and second slide blocks , a locking control assembly including a movable seat forming a groove and a tongue control plate movably mounted to one side of the locking control assembly , and a winglet assembly including first and second winglets both having a boss movably received in the groove of the movable seat and both being respectively and rotatably coupled to the first and second slide blocks . thus , when the movable seat is driven by a handle , the movable seat moves the first and second slide blocks to withdraw first and second latch bars to unlock the fire door and when the fire door is closed , the tongue control plate is actuated to allow the movable seat to return to the locked condition and the first and second latches and a tongue are stretched out to realize three - directional locking .