Abstract: The shape design for measuring flume is an important part of the application of measuring flume in irrigation areas.At present, there is no perfect standard to follow.In order to solve the problem of shape design in the practical application of right triangle measuring flume, the design criterion of measuring flume shape was proposed based on the limitation of submergence degree, backwater height and upstream Froude number.On the U-shaped channels of two types and three slopes, five right triangle measuring flumes were built with steel formwork for irrigation area test.A flow formula including channel bottom slope was established, and the empirical formulas of submergence threshold, backwater height and upstream Froude number were fitted.The results showed that the accuracy of the flow formula with slope ratio was high, the average relative error was only 1.88 %,the maximum relative error was 5.56 %,and the proportion of data with relative error within ±5% was 98 %.The quantitative relationship between the submergence threshold, backwater height, upstream Froude number and the throat width of the measuring flume was obtained through three empirical formulas, which can be used for the shape design of the measuring flume.Based on the shape design criteria and empirical formulas, a right triangle measuring flume shape design method was established, in which the submergence degree was less than the corresponding submergence threshold under the maximum flow rate and the minimum flow rate, the backwater height was less than the super height of the channel bank top under the maximum flow rate, and the upstream Froude number was less than 0.5 under the minimum flow rate.The research results can be used for similar measuring flume shape design.