Abstract: The existing reservoir flood control safety design is largely governed by a single variable, disregarding the correlation between factors and failing to accurately reflect the true nature of flood events. In this study, the combined distribution of the annual maximum flood peak and volume is constructed by using the two-dimensional Copula function. To magnify the typical flood hydrograph, various groups of peak and volume combinations were chosen using the two variable return period as the flood control standard. The reservoir flood routing was used to obtain a series of design water levels, and it is this series’ variation range that is then determined. In order to research how various design return times affect the reservoir’s design value, this paper studies the reservoir safety design based on flood control return periods. Four traditional return periods（Joint return period, concurrent return period, Kendall return period and survival Kendall return period） commonly used at present are compared and analyzed. Taking Yangxi Reservoir located in Duliujiang reach of Liujiang River basin as an example, this paper calculates design water level of the five return period standards, and discusses the rationality, reliability, and advantages of flood control return period in reservoir flood control safety design. The results show that the risk region of flood control return period at any return period level is definite and unique. There is a coupling relationship between the contour shape of flood control return period and flood discharge interface. The design water levels under different return period standards vary greatly, and basically meet the rule of TOR ＞ TF ＞ TKD ＞ TSK ＞TAND. The flood control capacity corresponding to the flood control design parameters under the flood control return period corresponds to the project flood control standard, which can reduce the project cost, effectively resist the flood risk, and ensure the safety of the project.