Abstract: The comprehensive safety factor methods and partial safety factor expressions should be adopted for the formulae to calculate the stability of anti-floating anchor and anchor anti-floating system. The model for the stability of anchor groups can be simplified as that of single anchor, the fracture surface is assumed that the upper part is cuboid and the lower part is cone, and the depth of conical tip is the sum of the fixed anchor length for calculation and free anchor length. The whole anti-floating bearing capacity of the anchor group is the sum of that of the single anchor. The anti-floating bearing capacity of the single anchor is the sum of the weight of soils inside the fracture body and the frictional resistance supplied by cohesive force on the assumed fracture surface divided by the partial safety factor, which is 1.5 and 3.0, respectively. In the formula for calculating the stability of anchor anti-floating system, the design resistance value is the sum of the design of values anti-floating bearing capacity of uplift piles and anti-floating anchor and the standard weights of buildings and permanent loads on them divided by safety factor of 1.05, and the design value of buoyancy is the hydrostatic pressure at the foundation bottom of buildings.