Abstract: According to the theory of three-dimension coupling-control in soft rock roadway, as the later-strengthening supporting system, bolt-injection supporting is very important to stain the whole supporting system stable, whose strengthening effect is directly related to the stability of the roadway. In order to gain the better effect of bolt-injection supporting. In this paper, the mechanism of bolt-injection supporting, the principle of the coupling effect between bolt-injection supporting and surrounding rock, and the stress-strain effect of bolt-injection supporting have been analyzed. It concluded that the bolt-injection strengthening craft must be combined to the process of surrounding rock deformation, formed a three-dimension coupling integer with the character of surrounding rock both in time and space. Only keep the deformation under control, could the favorable strengthening effect be gained, keeping the roadway stable wholly.