The differences of whether the powerhouses are supported by systematic anchors are studied with the method of numerical analysis to explore the influence of systematic anchors on the stability of underground planthouses.The results show that systematic anchors don’t influence the principal stress of wall-rocks much while they can increase the holistic stability.They reduced the average displacement by 28.07%,the displacement at vaults and tops more than 34% and the depth of the plastic damage zone at the main powerhouse and end chambers by 2.2~2.4 m.