Abstract : To reveal the process , mode and dynamic mechanism of convective cloud merging and provide theoretical support for the forecast of disaster-causing weather , by taking the process of convective cloud merging on July 1 , 2023 from Jingdezhen to Tunxi as an example , and using the fused multi-source data and radar UW retrieval technology as well as the horizontal wind vector method , this paper calculates and analyzes the high- resolution three-dimensional wind field and the related physical quantities on the isentropic surface at the middle and high levels . The results are as follows : (1) This convective cloud merging went through the three stages of cell development , cloud bridge connection and cloud core merging. After the merging , the convective cloud and precipitation intensity were strengthened , triggering the occurrence of short-time heavy precipitation . (2) There are two ways of cloud merging : one is the expansion of cloud echo forming a cloud bridge connection , and the other is the movement and merging of one cloud system to the other. (3 ) The cloud growth , development and merging occur in the high wind speed inlet zones and the low-level jet exit zone with positive isentropic potential vorticity advection . At the same time , the radar echo with merging cloud area has a large pressure gradient force and rotational wind . (4) Frontogenesis plays a significant role in the growth , development and merging of convective clouds , and is easy to induce the vector divergence increase and potential temperature change in the vicinity of the surface wind onvergence line and high altitude areas . To sum up , the mechanism of convective cloud merging and short-time heavy precipitation is summarized . Specifically , the high wind speed inlet zone and the low-level jet exit zones are the key conditions for cloud merging due to the interaction of positive isentropic potential vorticity advection , updraft and downdraft inside and outside the cloud , and the pressure gradient force and rotational wind in the cloud bridge area strengthen the wind field convergence uplift. Meanwhile , the frontogenesis below the mixed layer also plays an important role , especially near the surface wind convergence line and in high altitude areas , where it induces potential temperature change through enhancing vector divergence , leading to frontogenesis and promoting the growth , development and merging of convective clouds .