Combining the Mindlin elastic displacement solution with the elementary theory of finite element, in this paper, the shear stress distribution of pressure-dispersive anchor is calculated. Its work performances were compared with those of tensile anchor. According to the in-situ pull-out test of pressure-dispersive anchors in weak rock stratums, it is proven that the bearing capacity of pressure-dispersive anchor increases rather evidently than that of tensile anchor under the same condition and the effect of spacing between load-supporting bodies on the bearing capacity of pressure-dispersive anchor is analyzed. The analysis results of this paper can offer some references to the engineering application of this new type of anchor in the future.