With the numerical simulated data of the storm, the structure and evolution of the helicity, superhelicity and their dynamical influences on the development of the storm are investigated. 原有对流单体在原地维持成熟的结构，表现出较强的稳定性，而分裂出的新单体在移动过程中，逐渐向成熟位相发展，并且又分裂出新的单体。