The room temperature curing process was proposed to fabricate the Fe/epoxy composite. The effect of annealing temperature on the microstructure was investigated. The results show that the interplanar spacing of the (020) plane increased firstly then decreased, while the dislocation density decreased firstly then increased. The maximum and minimum values of the interplanar spacing and dislocation density are 2.39 nm and 0.31 nm-2, respectively when the annealing temperature is 80℃. When the annealing temperature improved above 80℃, the Fe/epoxy composites become dense without voids and the phase boundary between Fe and epoxy closes together. The size of Fe particle enlarged obviously from 15.58 μm to 18.26-21.74 μm when the annealing temperature improved from 60℃ to 80-120℃. When the annealing temperature increased from 60℃ to 80℃, the microhardness improved from 29.46 HV to 39.32 HV and sustained to 39.12 HV when the annealing temperature increased to 100℃, then decreased to 28.48 HV when the annealing temperature increased to 120℃.