The invention discloses a vehicle-mounted overload monitoring device for a truck, and belongs to electronic monitoring equipment. The vehicle-mounted overload monitoring device comprises a truck loading capacity information collecting module, a collecting data processing module, a data information display module, a voice broadcasting module, a wireless communication module, a truck ignition control module, and the like. The vehicle-mounted overload monitoring device has the advantages that an ignition system of the truck is controlled by the collected truck loading capacity information; under the condition of truck overload, the ignition system of the truck is cut off, and the truck cannot be started at the original place, and can only be started after the unloading meets the requirement; the overload degree of the truck is displayed by different colors, the truck loading capacity information is displayed on a display screen in real time, and the voice broadcasting is performed; by arranging a wireless communication module, the data exchange between an overload control station and the truck is convenient, and the truck loading capacity information is monitored in real time.