The utility model discloses a substrate conveying device which comprises a base, a substrate supporting platform, a support plate, two pairs of main guide rails, two pairs of spoiler guide rails, two pairs of spoiler upper guide rails, connecting shafts and a motor, wherein the substrate supporting platform and the main guide rails are fixed on the base, the support plate is fixed on the substrate supporting platform for supporting a substrate, the spoiler guide rails and the spoiler upper guide rails are respectively connected to two sides of the main guide rails, the connecting shafts are mutually connected for conveying the substrate, and the motor is respectively connected to conveyor belts on the main guide rail and the spoiler guide rails for providing power. The substrate conveying device also comprises a retainer and a plurality of amplifying plates, wherein the plurality of amplifying plates are respectively arranged on two ends of the support plate along the direction of the main guide rails, the retainer is arranged on one side of the support plate, which is close to the spoiler guide rails, and an induction unit and a control unit are arranged in the retainer for controlling the position of the substrate. According to the substrate conveying device, the substrates with sizes within 650*460mm and weights within 5.0kg can be conveyed and the mounting precision can be ensured.