Abstract: To ensure the safe operation of the steam generator (SG) in the nuclear power system is of great importance. A number of threedimensional thermalhydraulic SG analysis codes have been developed which used for SG thermal safety analysis and design reference. In order to develop a domestic advanced SG analysis code, the NuTHeL of Xi’an Jiaotong University developed the threedimensional SG thermalhydraulic analysis code STAF based on the drift flux model and porous media. The initial program version was STAF1.0, which was characterized by simplifying the Utube bundles of primary side into a onedimensional flow, and thermal coupling with the secondary side (threedimensional porous media model) was realized. The election of heat transfer model, resistance model, turbulence model and drift flux model has also been discussed. Combined with the FRIGG experiment data, the thermalhydraulic calculation accuracy of STAF is better than the ATHOS code. For simulating the threedimensional flow of Utube bundles on primary side, the refined modeling combined with the porous media has been adopted in the STAF-CT (STAF2.0). The mesh of bundles on secondary side and primary side was overlapped, which was used for full threedimensional thermal coupling between the primary and secondary sides. STAFCT characterized by full threedimensional thermal coupling between the primary and secondary sides, which could obtain more reliable distribution of thermalhydraulic parameters compared with STAF1.0. The above two SG codes are both developed based on commercial CFD platform (ANSYS). In order to avoid the copyright restrictions, STAF3.0 version abandoned the commercial CFD platform, developed on the open source CFD platform OpenFOAM instead. The OpenFOAM does not possess all the physical models that STAF needed, extra models have been developed and implanted into OpenFOAM, all the functions of old versions (STAFCT) were also retained and the computing results have been tested well. To take full advantage of the multicore processor, the parallel function was also upgraded, which effectively improves the computing efficiency compared with serial computing. Finally, typical applications of the STAF series have been introduced, such as SG thermalhydraulic analysis, enhanced heat transfer with axial economizer, tube plugging conditions, 16N migration in secondary side of the SG, corrosion deposits on tubes and marine conditions. The STAF series of programs have a wide range of functions and applications, and can provide important reference for the development of the SG threedimensional thermalhydraulic analysis program for advanced nuclear power systems, as well as provide tools to support new generation steam generator design optimization and safety analysis.