A vehicle load metering device has a displacement sensing module, a signal processing/transmission module, and a signal receiving/processing module. The displacement sensing module has multiple displacement sensors respectively mounted on flexible supporting devices of a vehicle suspension system. Each displacement sensor is connected to two supporting boards of the corresponding flexible supporting device to meter amount of displacement between the two supporting boards. The signal processing/transmission module transmits the signals that are detected by the displacement sensors to the signal receiving/processing module. The present invention provides a vehicle load metering device that may assemble on the vehicle conveniently and detect the load of the vehicle accurately.