Abstract: Applicability of trapezoidal cut-throated flumes to flow measurement in terminal trapezoidal channels was preliminarily explored in this work. Considering the geometrics of trapezoidal sections, we designed trapezoidal throat throat and experimentally tested it in trapezoidal cut-throated flumes of different throat contraction ratios (0.4-0.7) under different discharges (15-72 L/s), examining the hydraulic performance of the flows under 48 free flow working conditions. Water level was measured at 15 cross sections and variation in water surface profile was obtained; based on the principle of critical flow, dependency of the flume discharge on various factors was examined and a discharge formula was established. And we analyzed the longitudinal variations in Froude number, backwater depth and head loss, along with the precision of measurements. Results show that under free flow conditions, no critical flow will occur when the throat contraction ratio is larger than 0.6 and the channel flow rate lower than 16 L/s. When the contraction ratio is in the range of 0.4-0.6, the formula has a satisfactory accuracy of relative error within 4.8%; when in the range of 0.5-0.7, the backwater height is less than 3.15 cm and the average head loss is about 4% of the working head. A comprehensive analysis reveals that the contraction ratio of 0.5-0.6 is a suitable range for flow measurement and this new device would be useful for the irrigation systems in North China.