A new type of pressure-cast-in-situ pile with a spray-expanded frustum (PPSF) developed in recent years, which is constructed by spiral multifunction auger drill. Due to the expanded body of PPSF, the mechanical properties of pile-soil interface are greatly improved. The traditional settlement calculation method of tapered pile is not applicable to PPSF due to the assumption of cylindrical cavity expansion theory, and the relevant calculation methods of squeezing branch pile cannot explain the strengthening effect of the surface normal resistance on the tangential resistance at the lower frustum of the expanded body. To get a simplified approach for load-settlement prediction of PPSF, considering the extrusion effect of the expanded body, a load transfer model is proposed to simulate the relationship between end resistance and corresponding settlement of the expanded body. The load-settlement responses from two field tests are compared to illustrate the reliability of the present method. Furthermore, the effects of embedment depth, diameter and frustum angles of expanded body on the bearing capacity of PPSF are studied. The research results show that the settlement calculation method of PPSF is reasonable and reliable (with a maximum error of 12.6%). With the distance from expanded body to pile end increases from 0.5 m to 6.5 m, the bearing capacity decreases from 4993 to 4770 kN, with reductions ranging between 1.1% and 4.5%. The bearing capacity increases by approximately 11.4% for every 100 mm increase in the diameter of the expanded body.