The invention provides an object-oriented hydrodynamic modeling element management method. The method comprises the steps of obtaining multi-class basic data of hydrodynamic modeling, and building an object-oriented model element of flood analysis modeling according to the multi-class basic data, wherein the object-oriented model element comprises a one-dimensional river network model element, a two-dimensional shallow water model element and a city pipe network model element, the one-dimensional river network model element comprises one-dimensional river network data and a hydrology sequence, the two-dimensional shallow water model element comprises two-dimensional grid data and a time sequence, and the city pipe network model element comprises a subsidiary catchment area, a pipe section, a node, a hydrology station network, a curve set, a time mode and LID control; providing creating, deleting, drawing and importing functions for each model element. According to the object-oriented hydrodynamic modeling element management method, by obtaining basic data related to flood, a one-dimensional city pipe network, a two-dimensional city pipe network, a one-two dimension-coupled city pipe network and a pipe network two-dimensional model element are built, so that a flood analysis model which is suitable for country pipe networks and city pipe networks is conveniently put up, and the flood analysis model is suitable for subsequent flood analysis of different areas.