It is introduced that a new can be described as GPD(Generalized Pareto Distribution) by which the probability distribution of the extreme precipitation events can be fitted. The extreme precipitation events are simulated by means of GPD and GEV with estimated parameters by using L-moment method and the quantiles of rainstorm or severe precipitation events with a given return period are estimated in Chonqing area. Numerical simulations show that POT(Peaks Over Threshold)-based GPD is advantageous in its simple operation and practically to increase effective sample size of the primitive series, and producing steady high-precision fittings in the whole field of values(including the high-end heavy tailed). In comparison, BM(Block Maximum)-based GEV is limited, to some extent, to the probability and quantile simulation, thereby showing that GPD is an extension of GEV, the former being of greater utility and higher significance to climate research compared to the latter.