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By using the conventional meteorological data, infrared cloud images of th FY4A satellite and doppler meteorological radar data, this paper analyzes a severe convective weather case occurred on 17 May 2019 in the central BeijingTianjinHebei region, accompanied by a strong hail, shortterm heavy precipitation and shortterm strong winds. To further reveal the environmental conditions of the convective storm formation and the mechanism of backward propagation, the Variational Doppler Radar Analysis System (VDRAS) and meteorological data of a national automatic weather station are used. The results show that under the largescale background field being favorable for the occurrence and development of strong convection, the convection system around the central BeijingTianjinHebei region developed rapidly. The convection system was triggered by a southward moving ground convergence line at the BeijingLangfang border, which was the confluent area between the southeast air flow from the Bohai Bay and the strong northeast cold air flow generated by the cold pool formed by the strong convection weather in the BeijingTianjin region earlier. It is shown as a backwardpropagating multicell storm. The main reasons for the backwardpropagation are the strong wind shear in lower atmosphere (0 to 3 km) and the positive feedback effect between new and old storm cells.