Radiation transfer in low-density foam is influenced by the external radiation field which impacts on the foam when the size of plasma created in laboratory is not large to be opatical thick. The radiation transfers of different photon groups are sensitive probes of the conditions of the medium through which they propagate. The temporal behavior of photon groups to which the plasma is optical thin is quite different from that of photon groups to which the plasma is optical thick. The breakout times of different photon groups through the foam are distinguishable different in experiment when we measures them at the end of foam. The multi-group supersonic radiation transfer behavior in low-density foam is studied both by multi-group transfer numerical simulation and experiments. Two characteristic photon groups are chosen to do experimental research on the multi-group transfer behavior in low-density CH foam. A time-resolved chromatic streaked X-ray spectrometer measure the breakout of the two photon group from the far end of the foam cylinder. The distinguishable transfer time delay between two groups is observed.