A new sampling method for storm pattern samples: precipitation natural sliding sampling was designed in this paper. According to this sampling method which is used in the urban rainstorm intensity formula and the design technique for determining rainstorm pattern, the four sampling methods—return period sampling, annual maximum sampling, natural field sampling and precipitation natural sliding sampling, are analyzed and compared by using the minute precipitation data at the Shapingba National Basic Station of Chongqing from 1961 to 2016. The results showed that precipitation natural sliding sampling has the advantages of simple flow and higher sample representation. This method can provide a new reference for formulating rainstorm intensity formula and designing rain pattern sampling in future.