Abstract: The structure and property of materials under neutron irradiation is an important basis in the engineering design of China Fusion Engineering Testing Reactor (CFETR). Tungsten (W) is considered as the most promising candidates of plasma facing materials (PFMs) in CFETR, while neutron irradiation can lead to an increase in hardness and a decrease in toughness of W-PFMs, seriously affecting the safety and stability of CFETR. Due to the lack of fusion neutron sources, the modelling and simulation of defect structure and corresponding mechanical properties of fusion materials under neutron irradiation are of essential significance. With the support of national key R&D program, W as the model material is taken to establish a simulation platform for neutron irradiation in metals. This platform will address the common and critical technical problems in the modeling and simulation of neutron-irradiated materials, and realize the multiscale modeling for fusion materials from neutron-induced displacement cascade to microstructure and thermal/mechanical property. Based on the platform, the performance of materials after fusion neutron irradiation can be predicted.