Advanced nuclear systems, such as fusion systems, generally have features of large size, complex structures, spatially heterogeneous distribution of components and materials, and high energy and high flux, as well as a wide and complex energy spectrum of neutrons. Compared with traditional nuclear systems, these features have brought unprecedented challenges to neutronics design and analysis. To confront these challenges, the FDS Team has made significant progress in the development of neutronics methods and the comprehensive simulation code Super Multi-functional Calculation Program for Nuclear Design and Safety Evaluation (SuperMC). Furthermore, the FDS Team has been developing the High Intensity D-T Fusion Neutron Generator (HINEG) and has performed a series of neutronics experiments. Based on the developed methods, codes, and facility, a series of fusion designs and analyses has been carried out, including the design of FDS series reactors as well as the ITER neutronics analysis.