Based on the field test results of rock socketed uplift piles, the ultimate uplift capacity is determined by graphical methods that applied on load-displacement curve, and the determined value is compared with the test value. The results show that the initial straight line gradient method is limited by the displacement increment of 3.8mm, and the value of ultimate bearing capacity of rock socketed uplift pile is 42.0% ~ 102.4% of the test value, with an average of 66.0%, which is conservative; The value of double straight line intersection method is 85.2% ~ 98.5%, with an average of 94.8%, which is more appropriate; The L1 value of L1-L2 method is only 15.5% ~ 64.1%, with an average of 29.7%; The L2 value method is one of the criteria for determining the ultimate bearing capacity in the current pile foundation code. When the foundation deformation has strict and special requirements, L1-L2 method can be used to analyze the bearing deformation of test piles, but it is not suitable for determining the ultimate bearing capacity.