Abstract: There is a complex multi-physical field coupling mechanism in the core of nuclear reactor. For example, the power distribution of the nuclear reactor is a very important parameter, the power of the core is determined by the fission power of the fuel, and the fission power is closely related to the distribution of neutron flux. In order to accurately obtain the core power, it is necessary to establish a neutron diffusion and fuel cross section model to realize the coupling of physical and thermal parameters, which is called neutronic thermal-hydraulic coupling analysis. There is a danger of impurity deposition on the cladding surface of a nuclear reactor during long-term operation, which will increase the surface temperature of the cladding and endanger the safety of the reactor. In order to accurately obtain the thermal parameters of the reactor core under long-term operation, it is necessary to establish a deposition model and couple with the thermal parameters. The above coupled physical fields are very common in reactors, but the traditional nuclear reactor core analysis method cannot meet the requirements of high fidelity and multi-model calculation, and there are some problems in cross-platform computing, such as data transmission distortion, low calculation efficiency, analysis scale incompatibility and so on. In this paper, based on the full core channel level three-dimensional thermal-hydraulic characteristics analysis code CorTAF developed by the team, the model of core thermal coupling and impurity deposition was established and implanted into the CorTAF code, which expands the calculation function and forms the CorTAF2.0 version. Relying on the OpenFOAM, CorTAF2.0 not only can be used in the thermal-hydraulic calculation and analysis of the whole core channel level, but also has the ability to calculate and analyze the neutronic thermal-hydraulic coupling in the core channel level and the impurity deposition in the core channel level under long-term operation. The neutronic thermal-hydraulic coupling module can calculate the neutron flux distribution and power distribution in the whole core by solving the neutron diffusion equation. The sediment calculation model and thermal resistance model were constructed in the impurity deposition module, which can obtain the scale distribution of impurity deposition in the whole core and the thermal-hydraulic influence after deposition, and the two modules were verified by benchmark questions and experiments. The work of this paper is of reference and reference significance for the coupling analysis of multi-physical fields in the whole core of PWR.