Based on limit equilibrium theory in three-dimension, the pullout uplift bearing capacity of circular anchor plates in loess under the loading which is vertical to the plate surface is studied. The study considers the equation of loess failure around anchor plates, normal stress and shear stress on the failure plane and buried depth rate h/D when the plates are being uplifted. It is found that the pullout uplift bearing capacity increases with the buried depth, and will reach the limit when the buried depth reaches a certain value. When h/D=1 to 2, the overlying soil weight puts slight effect on pullout uplift bearing capacity; when h/D=4, suction between the soil and the anchor plate contributes more than the overlying soil weight to the results; what is more, in the case of h/D>4, the overlying soil weight plays a decisive role in the pullout uplift bearing capacity. The comparison between the theoretical calculation and the test results of other researchers demonstrates that the theoretical results show consistency with the test results; thus verifying the correctness of the theory. It provides a valuable reference for the design of pullout uplift anchor plates.