The construction process of shallow buried large span and small clear distance tunnel is complex and the construction progress is slow. The step method of micro-pile locking foot was proposed for the construction of shallow buried large-span and small clear distance tunnels, and the mechanical action mechanism of the step method of micro-pile locking foot was analyzed. The micro pile model can be better applied to the mechanical analysis of the strong lock foot, effectively play the support potential of the foot lock, and expand the application scope of the bench method. The step method of micro-pile locking foot can achieve the construction effect equivalent to CD method. The results of theoretical analysis and engineering field monitoring measurement were further compared and analyzed, which showed that the practical application effect of step method of micro-pile locking foot was good. The results can provide a new idea for the construction of shallow buried large span and small clear distance tunnels.