With the rapid development of China"s power industry, the problem of uplift bearing capacity of tower foundation in transmission line is becoming increasingly prominent. The determination of failure mode of layered foundation and the calculation of uplift bearing capacity are the key problems to be solved. Based on the existing research results, the fracture surface equations of different foundation are put forward, and the bearing capacity calculation formula of the pile with rock socketed and enlarged bottom is derived by using the limit equilibrium method. According to the centrifugal model test results of 9 different belled piles, the axial force distribution of the pile body, the friction resistance curve of the pile side and the load displacement curve are analyzed, and the failure mode and bearing capacity of the test pile are comprehensively compared with the theoretical calculation value. Research conclusions: (1)The results show that the upper overburden layer has little influence on the axial force and the side friction of the pile body, accounting for only 5% ~ 10%, and the axial force and the friction of the pile in the lower rock mass account for 90% ~ 95% of the total; (2) With the increase of rock socketed depth and pile diameter, the ultimate uplift bearing capacity increases linearly, and the influence of rock socketed depth parameters on the bearing capacity of pile is obviously greater than that of pile diameter;(3)the rock mass failure mode of the upper overburden rock socketed belled belled pile is trumpet shaped and basically consistent with the curve form of the fracture surface fitting function, and the fracture surface range is about 3 ~7;(4)The difference between the measured value of uplift bearing capacity and the theoretical value is kept within 7%, which proves that the fracture surface fitting function equation and the uplift bearing capacity calculation formula of the pile have high reference and application value.