Limit envelope method is employed to obtain the uplift bearing capacity of caisson foundation under inclined load. Functions of ultimate uplift bearing capacity of caisson foundation under horizontal load and vertical load are presented based on 15 sets of model tests and reasonable assumptions. Through analyzing the relationship of coefficients of horizontal and vertical ultimate bearing capacity respectively vs. ratio of length to diameter, the calculation methods for the bearing capacity of caisson foundation under horizontal load and vertical load are obtained. Furthermore, a power function between normalized ultimate horizontal bearing capacity and normalized ultimate vertical bearing capacity of caisson foundation in the presence of varying ratio of length to diameter and angle of load i obtained according to the diagram of failure envelope between the two normalized values. And then the ultimate bearing capacity of caisson foundation under inclined load is obtained.