The radiation force on a moving atom in a bichromatical travelling field is investigated in this paper. The relation of the atomic stimulated transition rate and the radiation force on the atom with its velocity in a bichromatical travelling wave is obtained by numberical calculation. Compared with that in a monochromatical travelling or a standing wave, the result in the bichromatical field have its own character, which is useful in the investigation of laser cooling of neutral atoms, selection of atomic velocity and atomic mometum diffusion.