College of Geo- exploration Science and Technology，Jilin University，Changchun 130026，China

In seismic wave travel- time calculation，fast marching method (FMM) has the characteristics of high precision and efficiency，but its narrow band extension has to find the minimum travel- time for every time， which is very time consuming which when the grid nodes are massive． On the premise of guarantee accuracy，the authors made improvements on the heap sorting method，and introduced complete ternary tree heap sorting method into FMM of seismic wave travel- time calculation in order to improve the computational efficiency． The experimental results show that seismic wave travel- time calculated by FMM based on complete ternary tree has the same precision with FMM based on complete binary tree one，and the former is higher in efficiency than the latter，which increases by about 10%。