The invention provides a whole-vehicle electronic toll collection (ETC) and vehicle guidance method and system. The method comprises: acquiring vehicle information from on board units (OBUs) via a pre-reading roadside unit, screening valid vehicles and invalid vehicles, and storing the valid vehicles into a queue to be released; releasing the queue to be released, transferring the queue to be released to a queue to be weighed, intercepting the invalid vehicles and forcibly guiding the invalid vehicles to an MTC (Manual Toll Collection) lane; weighing the vehicles in the queue to be weighed, binding the weighing information with a pre-read valid label identification address logic, and transferring the weighed vehicles to a queue to be transacted; performing fee transaction between a front transaction roadside unit and the OBUs of the queue to be transacted, intercepting and forcibly guiding the vehicles to leave and ETC lane and enter the MTC lane if fee collection fails, and deleting the vehicles leaving the ETC lane from the queue to be transacted. The method and the system solve the problems about manual processing needed after the fee transaction fails and guidance of transferring the vehicles failing in transaction to the MTC lane.