Abstract: In this paper a potential application of free electron laser (FEL) was pointed out. It was also shown in a previous paper[3] that Threshold chemical reaction method (TCR) for laser-based separation of uranium isotopes in molecular forms has advantage of avoiding second excitation over the atomic and other molecular forms. It has larger single-pass separation factor than the atomic and other molecular forms in principle. The requirements for laser adopted in the method can be met by the available technology of FEL driven by electro-static accelerator. It is able to product highly enriched uranium in a small scale of 10kg per year using TCR.