Abstract: Based on the mechanism of reinforced arch formed by anchor, according to elasticity theory, it established a mechanical model of anchor reinforced arch in surrounding rock. Through the mechanical analysis of reinforced arch, it obtained the relationship of arching load, anchor length, ground stress and surrounding rock parameters. Considering deformation compatibility conditions and reinforced arch failure modes of lining-surrounding rock, it deduced the formulas of reinforced arch thickness. Through the parameter analysis, it got the influence law of ground stress and surrounding rock properties for arching load and reinforced arch thickness.