This paper presents the assessment of the computational fluid dynamics (CFD) methodology for simulating the boiling flow in the Pressurized Water Reactor (PWR) rod bundle. The method includes the Eulerian-Eulerian two-fluid model coupled with the improved wall heat partitioning model. The effects of key phenomenological models are investigated based on the experimental data of vertical pipes. Then the integral validation of the method is carried out based on the NUPEC PWR Subchannel and Bundle Test (PSBT) International Benchmark, including the single sub-channel experimental data, and the full length of a PWR fuel assembly with multiple 5 × 5 spacers grid experimental data. The results agree well with the experimental results, which indicate the promising application of the present method for modeling the boiling flow under high pressure. Based on the validated method, the three-dimensional boiling flow in the fuel rod bundle is investigated, including the rod surface temperature, the bulk fluid temperature and the void fraction.