Side Dump Trailer through the hydraulic cylinders on both sides to realize the cargo box 70 degrees side tilt unloading, low center of gravity, U-shaped cross-section design to reduce the material residue. Equipped with multi-stage telescopic baffles, the unloading width (2.5-4 meters) can be adjusted to accurately control the shape of material accumulation. Advantageous scenarios include railroad roadbed paving, slope trimming and other strip area operations, single unloading efficiency is increased by 40% compared with the back-turning type.