Method for inquiring into design flood hygrograph

The invention provides a method for inquiring into a design flood hygrograph. The method includes the steps that the first frequency is determined to be the standard frequency; under the standard frequency, the design flood hygrograph is obtained; on the premise that it is ensured that the design flood peak and the design flood volume in the design flood hygrograph are not changed, the smooth standard design flood hygrograph is obtained by conducting smoothing on a zigzag area on the design flood hygrograph; the standard design flood peak and standard design flood amounts of all duration time periods are obtained according to the standard design flood hygrograph; the standard design flood peak serves as the flood peak of typical floods, the standard design amounts of all the duration time periods serve as the flood amounts of the typical floods of all the duration time periods, and the design flood hygrograph of at least one second frequency different from the standard frequency is inquired into.