The trends of water and sediment, abrupt change point, and periodic features of mainstream Huaihe River in the recent 66 years were examined via cumulative anomaly, M-K test, R/S analysis and wavelet analysis. The observed water and sediment data during 1950-2015 at Wujiadu hydrological station, a typical station, was analyzed. The real causes of abrupt changes and change trends were researched in depth as well. In general, the annual runoff of mainstream Huaihe River did not undergo obvious increase or decrease; yet the incoming sediment displayed a remarkable declining trend until 2000, after which the incoming sediment tended to be stable. The fluctuation of incoming sediment experienced two stages from large to small incoming, with the abrupt change happening during 1980-1984. Such decrement trend will last in the near future. The causes of such decrement of incoming sediment lie in reservoir blocking, agricultural plantation, artificial sand mining, navigation channel regulation, and river channel dredging. What’s more, the first, second, and third dominant periods of runoff are 18 a, 8 a, and 2 a, respectively; and in the near future low flow will continue; on the other hand, sediment discharge remained declining in general, with the dominant periods of 7 a, 17 a, 25 a, and 2 a; sediment concentration will also remain small in the near future, with its dominant periods of 23 a and 6 a. The research findings offer theoretical basis for the water resource management and channel exploitation of Huaihe River Basin.