Based on the conventional observational data, satellite images, automatic observational precipitation and NCEP/NCAR reanalysis data (0.25°×0.25°), the characteristics of dynamic and thermal field structure of a rainstorm affected by different systems in the northern part of Northeast China on 24 and 25 July 2018 are analyzed. The major conclusions are as follows: the rainstorm was caused by the warm front frontogenesis, and the rainstorm range was widespread on 24 Jul 2018. There appeared typhoon torrential rain on the typhoon movement path, manifested as a narrow rainfall belt on 25 Jul 2018. The rainstorm was caused by MCS (Mesoscale Convection System) activities, and each shorttime heavy rainfall corresponded to a low value center of TBB. The intensity of MCS in the typhoon trough was weaker than that in the warm front cloud system, but the intensity of precipitation was greater. Typhoon Ampil carried a large amount of warm and wet air, and the lowlevel jet stream on its east side transferred heat and water vapor to the north. The water vapor convergence was in the boundary layer, and the water vapor convergence intensity of the typhoon rainstorm was stronger than that of the warm front rainstorm, resulting in stronger rainfall. During the warm front rainstorm, the convergence and uplift of the windward slope of the Xiaoxingan Mountains were obvious. The highlevel strong divergence and topographic convergence uplift contributed to the rainstorm. During the typhoon and rainstorm, the convergence at low altitudes, especially the convergence of water vapor in the lower layer, made a great contribution to the rainstorm. The convergence zone was located near the typhoon trough, and the typhoon trough had the properties of a cold front.