The aim of this work was to explore the feasibility of the shaft-free UCG technique in strip mines or coal layers in a shallow depth, and to study the dependability of pushing through the gasification gallery with low-pressure fire seepage. In this article, the conditions of the model test are introduced, and the firepower seepage method is explained. The blind-hole electric ignition technique in the underground gasifier, the push-through technology for gasification gallery with intermittent forward-flow and counter-flow fire seepage combustion, and the underground gasification craft of the small-shaft gasifier are studied. On the basis of the above works, the results of the experiment were analyzed. The characteristics of forward-flow and counter-flow combustion seepage and influence law on coal gas quality are pointed out. Test results showed that the gas heat value heightened in a stepwise way with the rise in the wind-blasting volume, approaching stability.