The products of coal under fast pyrolysis experiments were carried to study the mechanism of coal products under the fast heat effects of deflagration. Several coal were studied here, such as young lignite, old lignite, long flame coal, coke and young anthracite. The experiments temperature is between 588 similar to 1313K, experiments heating velocity is 5000K/s, and with normal pressure, experiments time are is, 2s, 5s, 10s. Through fast pyrolysis experiments, products separated out from coal was got. There are CH4, CO, CO2, C2H4, C2H6, C-4, C-5, C3H6, C3H8. This mixed gas is flammable. The results could be used to study the combustion efficiency and mechanism of this special combustion course of different rank coal. This work is useful for study the coal using in the field of energy using and combustion. It may provide one new method to protect our environment tomorrow.