The deformation of rock mass around underground facility is confined by excavation face. Under the confinement

the spatial effect of excavation face is remarkable. Field test was performed to investigate the characteristics of the spatial effect of excavation face. An empirical hyperbolic tangent formula is proposed to describe the spatial effect. The stability of an underground cavern was analyzed using the proposed empirical formula. It is shown from this study that for a certain section

the spatial effect is not the most remarkable when the excavation face is passing the section. For rock mass of low quality

the spatial effect is less significant than that of high quality. The total displacement could not be obtained using the conventional monitoring method

which takes influence on back analysis of mechanical parameters of rock mass. The standard for stability control could be obtained using the principle of spatial effect. This study will benefit the understanding of the spatial effect and provide the reference for the stability control of underground facility.