The invention provides a freight dump trailer. The freight dump trailer comprises a trailer chassis and a carriage body arranged above the trailer chassis, wherein the carriage body comprises a plurality of front rollover carriage bodies capable of unloading independently arranged sequentially along the longitudinal direction of the trailer and a back carriage body. The total volume of the plurality of carriage bodies is equivalent to the volume of the entire carriage body in the prior art, so the volume of each carriage body is relatively small, the total weight of cargos in the carriage body is relatively light and the turnover risk is greatly reduced while dumping the cargos in the single carriage body. Furthermore, the cargos in one of the carriage bodies are dumped firstly, and the weights of another carriage body and the cargoes therein play a role in balancing weight in an unloading process. The carriage bodies, from which the cargos are dumped, can play a role in balancing weight while dumping the cargos in the last carriage body, so the turnover risk is further reduced. The freight dump trailer is provided with the plurality of carriage bodies and unloads the cargos sequentially for a plurality of times, so the unloading safety is very high.