Combining with the Chinese climate divisions, the paper divided the basin into seven sub-regions by clustering analysis for meteorological stations and using self-organizing map (SOM) neural network method. It analyzed the combination characteristics of multiple time scales of drought in Huanghuaihai River basin by using standardized precipitation index (SPI)，linear trend estimation and M-K trend test based on the daily precipitation data of 203 meteorological stations from 1961 to 2013.The results indicated that on annual scale, the downstream of Huaihe River has the highest drought frequency which reaches 37.74%. Drought of other regions of the basin presents intensified trend except north and west regions of the basin. On seasonal scale, northeast and north regions of the basin have the highest spring drought frequency. The downstream of Huaihe River basin have the highest drought frequency in summer and winter.The northern and central region have the highest drought frequency in autumn. The drought in small area of the basin shows a tendency to aggravate in spring and summer. The drought in most parts of the basin has intensified trend in autumn. The drought in the whole basin shows a weakensing trend in winter.