[en] The ITER toroidal field (TF) in-cryostat feeder system (ICF) locates in the main cryostat of the Tokamak.It consists of 18 segments, which form a ring by connectors and hang on the corresponding TF coil terminal area. During cooling down the components in the cryostat,the shrinkage of ICF is not synchronous with the TF coil. In this case, relative displacement occurs on the circumferential end surfaces of the neighbor segments, so that the function of displacement compensation is required on the connector. Researching on cooling process of the ITER TF ICF system, finite element method (FEM) was applied on the numerical simulation of the steady-state and transient temperature field in the ICF. The heat load and temperature distributions in ICF were worked out; furthermore, the temperature-time curve and deformation-time curve were also presented. The results show that active cooling is not required on ICF, the heat load and thermal stress is very weak. Meanwhile, the results will provide primary parameters for the design of connector with compensation function. (authors)