Abstract: This paper aims to study the causes and characteristics of the continuous rainstorm in Qingyang area of Gansu, and provide references for the severe rainstorm forecast and early warning in this area. The continuous rainstorm process in Qingyang from 17 to 22 August 2017 is analyzed by conventional meteorological data and diagnostic analysis technology. The results showed that: (1) the precipitation duration of the continuous rainstorm in earlier stage is short, intensity is large, distribution is uneven, and outburst is obvious. The medium duration is long, scope is wide, local precipitation intensity is strong, accumulative precipitation is large; In the later period, it has a long duration, wide range, uniform distribution and large accumulative precipitation. (2) low layer uplifting of low level jet and high-jet suction caused the development and maintenance of the rainstorm. (3) the mesoscale cloud cluster is active, with high degree of organization and long duration. (4) in the early stage, atmosphere is in a state of extreme high energy instability, and in the middle period, the energy of unstable energy decreases, and in the later stage, unstable energy decreases sharply. (5) specific humidity increase obviously in the early stage, jump value reached 4g/kg,and larger than the later period, the strong southerly airflow in the low layer of the atmosphere formed a strong upward draft of the synoptic scale..