The invention relates to the field of vegetable fresh-keeping transportation, and discloses a vehicle-mounted box for refrigerated transportation of vegetables. The vehicle-mounted box comprises an outer box body, a fresh-keeping box is arranged in the middle of the outer box body, the side surface of the fresh-keeping box is not in contact with the side surface of the outer box body, a supportingbaffle plate fixedly sleeved with the interior of the outer box body is arranged at the bottom of the fresh-keeping box, and the bottom of the fresh-keeping box is not in contact with the bottom of the outer box body. According to the vehicle-mounted box for refrigerated transportation of the vegetables, through the structural design that the fresh-keeping box is arranged in the outer box body and matched with a flow guide chamber and a heat exchange chamber between the fresh-keeping box and the outer box body, in the transportation process, ice blocks are placed in the heat exchange chamber,so that the fresh-keeping box is refrigerated and subjected to heat preservation, a ventilation pipe and an exhaust pipeline extend out of a vehicle to facilitate real-time ventilation in the fresh-keeping box, and the problems that vegetables in the fresh-keeping box breathe, the content of carbon dioxide in the fresh-keeping box is increased, the temperature in the fresh-keeping box is increased, and the fresh-keeping effect on leaf vegetables is poor are effectively solved.