Abstract: The C5G7-TD benchmark problems are established by Organization for economic development and cooperation Nuclear Energy Agency (OECD/NEA), to verifiy the calculation capability and precise of 3D non-uniform transient transportation calculation code. NECP-X is a numerical reactor physics calculation code developed by Nuclear Engineering Computational Physics Laboratory of Xi'an Jiaotong University. To better verify the space-time neutron kinetics module of high-fidelity neutronics NECP-X, the C5G7-TD benchmark problems are solved by the NECP-X employing faithful models of the core configuration and transient control parameters. For all cases, the NECP-X results are compared with the nTRACER transient simulation results. The results consisting of transient power behaviors and dynamic reactivity changes are presented. The results of the time consumption for three-dimensional cases and the detailed power distribution are also presented. Numerical results show that the results of NECP-X are with high precision and high resolution, the computational time is at the international leading level, and NECP-X can satisfy the requirements of high-fidelity calculation.