Abstract: In traditional Monte Carlo code relative to the neutron transport tracking process, the distances relative to the material boundaries must be computed frequently to determine the neutron transport length. However, if the neutron’s mean free path length is greater than the macro size of model, a huge amount of distances need to be computed. As a result, the computational efficiency of the neutron transport tracking will be degraded. The improved multi-regional delta-tracking method was introduced to solve the problem, in which the concept of the virtual cross-section was used to virtually homogenize multi-region in the model. Consequently, the efficiency of the neutron transport tracking could be improved theoretically without the distance calculations. The improved multi-regional delta-tracking method was incorporated into the MOSRT system, which was a multi-objective modeling and simulation platform for radiation transport system. Finally, the method was validated using the criticality benchmarks and its accuracy and efficiency are demonstrated.