Abstract: Seismic tomography is one of the main techniques exploring the inner structure and characteristics of the Earth. The focus of the paper is the use of Moser method in 2D first arrival wave travel time tomography. We used the basic principle of travel time tomography to improve the forward modeling of Moser shortest path method. Moreover, we proposed two ways to fix the existing problems in travel time and ray path calculation:1)using dynamic nodes to improve the precision of travel time calculation; 2) using multiple linked list hash to improve the efficiency of wave front nodes. By using the homogeneous medium model, we proved that the accuracy of the improved Moser method is much higher that of the original algorithm in forward modeling, with a relative error of 0.1% or less. Finally, we applied the improved Moser method to forward modeling calculation of Marmousi2 model. The resulted ray map agreed with the theoretical expectation, which proved the accuracy of improved Moser method.