Based on the field pull destructive test of 9 anti-floating anchor of screw-thread steel bars in a foundation pit anti-float project in Qingdao, the load-displacement characteristics of anti-floating anchor of screw-thread steel bars under different anchoring lengths were studied, and the bearing performance of anti-floating anchor of screw-thread steel bars was determined. The results show that the ultimate uplift bearing capacity of the anti-floating anchor of screw-thread steel bars with the same diameter is 681 kN for the 3.0 m and 3.5 m anchors anchored in medium-weathered granite, and 1 004 kN for the 4.0 m anchors anchored in medium-weathered granite. At the initial stage of loading, the displacement of anchor head increase linearly, and with the increase of load, the displacement of anchor head increase abruptly, all of which exceed 50 mm. The agreement between the hyperbolic function and the power function load-displacement curve model and the measured value is good when the load level is low, but is relatively poor when the failure is near, and the predicted ultimate tensile strength is much different from the measured value. The exponential function load-displacement curve model can predict the ultimate uplift bearing capacity of the test anchors with high accuracy and good agreement with the measured curve.