The utility model discloses a height-adjustable guide plate for cargo transportation, which relates to the technical field of cargo transportation equipment and comprises a first guide plate, the longitudinal section of the first guide plate along the width direction is n-shaped, the opening of the first guide plate faces upwards, and vertical first sliding channels are arranged at the tops of two ends of the first guide plate along the width direction. Extending parts are slidably connected into the first sliding channels, and first rotating grooves are formed in the two ends, in the length direction, of the bottoms of the two extending parts correspondingly; according to the conveying device, the extending parts at the top ends of the two sides of the guide plate can be driven to extend out of the first sliding channel through the adjusting mechanism, the two sides of the conveying belt are blocked to protect goods, the goods are limited in the guide plate, and the goods are prevented from sliding off from the conveying belt in the conveying process; in addition, the extending length of the extending part can be freely adjusted according to the size of the goods, meanwhile, the phenomenon that some small-size goods are popped up can be reduced, use is easy and convenient, the effect is good, and the goods damage rate is reduced.