Strong feedback phenomenon between the neutronics physical and thermal-hydraulic has an important impact on the design and safety analysis of pressured water reactor (PWR). In order to accurately simulate the strong coupling effect of neutron physics and thermal hydraulic in PWR, a reactor multi-physical coupling calculation code (ARMcc) is developed, in which the three-dimensional space-time neutron dynamic equation is solved by nodal expansion method (NEM) and nodal Green's function method (NGFM), the coolant temperature and fuel temperature are solved by single channel model and the cylinder heat conduction model respectively. The 3D IAEA benchmark, the 3D Langenbuch Maurer Werner (LMW) benchmark and NEACRP-L-335 benchmark are used to verify the neutronics model and coupling calculation solution ability respectively. The results show that: 1) the NEM and NGFM have high accuracy in solving the three-dimensional space-time neutron dynamics equation; 2) the results of neutronics and thermal-hydraulic coupling steady/transient calculation such as core relative power and fuel Doppler temperature are in good agreement with those of the NEACRP-L-335 benchmark, and the calculation accuracy is equivalent to similar software such as PARCS. Four coupled neutron physics and thermal hydraulic calculation modes are used to analyze the influence of different neutron physics calculation methods and thermal hydraulic calculation methods on the key parameters of PWR transient process in this paper. The results show that the mode of NGFM + FVM can more accurately simulate the core relative power peak and Doppler temperature.