Abstract: The wide floodplain of the lower reaches of the Yellow River, where more than 180 million people live， functions as a flood discharge channel with detention and desilting functions in high flood periods. The harnessing work has long faced the problem of how to guarantee the people’s life, property safety, flood detention and desilting in the floodplain. Wether the construction of dikes should be done or not is the focus of the prodem. To build the dikes with sediment detention function, researches were carried out using different models. Yellow River Institute of Hydraulic Research used the Xiaolangdi to Taochengpu river physical model to study two kinds of flood processes with regulation and non-regulation measures, and used different patterns of flood detention. This paper, by comparing different floodplain models with a wide range of flood inundation, flood detention rate,and settling of sediment, analyses different modes of floodplain detention and desilting and their influences, in order that the study may provide a strong scientific basis. The research results show that the inundation area in the model without protection embankment is more than that with protection embankment under two kinds of flood conditions; the model without protection embankment has greater sediment detention volume than that of the model with protection embankment under the condition of constant flood; the model without protection embankment has a total detention volume slightly less than that of the model with the embankment, and its sand dike has greater detention volume under large floods; the dike pattern of Gaocun below narrow-reach floodplain leads to more serious results under two kinds of flood conditions.