To improve the speed of constructing triangle irregular network (TIN), We propose an efficient Delaunay triangle network construction algorithm. Firstly, we divide the discrete points set into blocks according to a certain threshold to construct sub-block index binary tree, then, Delaunay triangle network for each block is constructed with Graham scanning technology, finally, the sub-blocks which have the same parent node are merged bottom-up. Compared with other algorithms by the experiment, the high efficiency in network construction of the algorithm in this paper is verified.