The invention relates to the technical field of express packing boxes, and discloses a multilayer real-time composite corrugated board express packaging box and a preparation method thereof. The express packaging box comprises a front side plate, an L-shaped plate is fixedly connected to the bottom of the front side plate, clamping grooves are formed in the front surface of the L-shaped plate, clamping blocks are clamped in the clamping grooves, a clamping rod is fixedly connected to the middle of each clamping block, a pull cap is fixedly connected to the bottom end of each clamping rod, andthe right end of the upper surface of the front side plate is movably connected to a right side plate through a rotating rod. According to the multilayer real-time composite corrugated board express packaging box and the preparation method thereof, a first connecting rod, a second connecting rod, first springs and limiting blocks are coordinated together, due to the fact that the first connectingrod and the second connecting rod are supported by the elastic force of the first springs, a bottom plate of the packaging box is fastened, deformation and damage of the bottom plate of the packagingbox caused by overweight of internal objects in the express packaging box are avoided, so that the quality of the express packaging box is improved, and therefore the probability that an express delivery is damaged is reduced.