Using conventional meteorological data,NCEP FNL reanalysis data (1° ×1°),wind profileradar data,blackbody temperature (TBB),and hourly precipitation data of automatic meteorologicalstations,the multiscale characteristics of the extreme rainstorm caused by Typhoon Lekima from 10 to 13August 2019 in Shandong are analyzed and the results are as follows. (1)The typhoon heavy rainstorm ismainly caused by the interaction of synoptic systems in the middle and low latitudes as well as the directinfluence of the typhoon inverted trough. Moreover,it is closely related to cold air. The intersection of thecold and warm air is conducive to the persistence of the stable precipitation in most parts of Shandong.The cold air intrudes into the bottom of the warm and humid air flow from the lower level to form a coldunderlying layer. Besides,with the warm and humid air flow gliding on this cold underlying layer,therainfall intensity further increases. (2)The change of the lowlevel jet index indicates the appearance ofprecipitation and the increase and decrease of the future hourly precipitation an hour in advance,and thepeak value indicates the period of heavy rainfall in the next three hours. It is predictive for the appearanceof the period of heavy rainfall and the precipitation intensity. The rapid expansion of the lowlevel jet tothe lower level corresponds to the beginning of shortterm heavy precipitation. It can be used for the shortterm nowcasting of heavy precipitation. (3)The intensity of negative Qvector divergence can indicate therainfall intensity in the next 6 hours. (4)The maximum precipitation of Shandong appears in Xihe Townof Zibo,which is related to the flared terrain towards the northeast and the inflow of northeasterly winds inthe lower troposphere. (5)The TBB field can more intuitively reflect the distribution and intensity ofprecipitation during the rainstorm process. The variation of the wind field in the ultralow level from thewind profile radar has important indicative significance for the rainfall intensity and the period of thehourly rainfall with maximum intensity.