A novel and efficient approach to threedimensional convex hulls is presented in the paper, compared with the QuickHull method , the quadratic extremalpoint is  employed to construct the convex hull in the method, combining with "conflict map" (ConflictGraph) of this bipartite graph structure to update the topological relations between the points outside the convex hull and the current convex hull. This algorithm's time complexity is O(nlgr)，and the experimental results shows that the algorithm is more efficient  compared with the QuickHull method（the average execution timeconsuming is reduced by 20%) .