In this paper we present a new reconstruction algorithm. This algorithm is based on the Advanced Marking Scheme (AMS), and it works with a two-dimensional threshold mfd decides if a node is on the attack path by judging the situation of the edge of the packet and the Hash value match, then consequently reduces the time of reconstruction and overhead and improves the accuracy. Simulation results from the experiments carried on in the network test-bed show that obtained results are the same as theoretical results. Performance analysis and simulation experiment results shows, compared with the conventional methods, two-dimensional threshold reconstruction algorithm improves the performance of IP traceback technique obviously.