The volcanic eruption is a complex fluid dynamic process of gas, liquid and solid mixtures. A correct understanding of this process is the key factor to study the volcanic eruption. On the basis of detailed investigation of volcanic bombs, volcanic debris and the published data of Laoheishan volcano in Wudalianchi area, this study evaluated dynamic processes of Laoheishan volcanic bombs and plumes using Eject and Plumeria softwares. The results show that the bombs ejected from Laoheishan volcano can reach a maximum height of 530 m and a maximum horizontal distance of 1, 000 m when ejection angle is 45°;t he maximum height of its volcanic plume is 4.7 km, and the plume head radius is 2.3 km.