The utility model discloses a device for ensuring the gap of horizontal steel bars. The device comprises a molding bed, wherein one side of the molding bed is provided with a steel bar gap regulating mechanism, the steel bar gap regulating mechanism comprises a transmission part and a steel bar lifting part, a plurality of guide rail clamps are arranged on the molding bed, the transmission part comprises a force transfer rod and a transmission plate, the transmission plate can vertically move along the molding bed and the guide rail clamps through being driven by the force transfer rod, the steel bar lifting part comprises a plurality of lifting arms symmetrically distributed along the center line of the transmission plate, the lifting arms positioned at the same side of the transmission plate are mutually parallel, in addition, the gaps between the adjacent two lifting arms are identical, the lifting arms are rotationally connected with the molding bed, the lifting arms are mutually engaged with the transmission plate and can rotate through being driven by the transmission plate, and a steel bar position limiting part is respectively arranged on each lifting arm. The device has the advantages that the structure is simple, the operation is convenient, the manufacturing cost is lower, and the requirement of different horizontal gaps of the steel bars can be met through rotating pull rod screw bolts and regulating the positions of position limiting pins.