A river flow velocity measurement system based on multi-conductance flow velocity measurement sensor is designed.The system consists of a multi-conductance velocity measurement sensor

a filtering and conditioning circuit

a field programmable gate array（ FPGA） and a display.The experimental results show that the measurement error of the system is less than 4 %

which indicates that the system is accurate and reliable.The system can be used to measure the flow velocity at different depth points on the river cross-section and multiply the cross-section area of the corresponding part of the river to calculate flow of the part.The sum of the flow volume at different depth is the flow of the whole section.