An integrated simulation approach, which couples Monte Carlo ray tracing (MCRT) and Gebhart methods, is proposed to simulate solar radiation transfer in a solar power tower system with a cavity receiver. The MCRT method is used to simulate the solar radiation transfer process from the heliostat field to interior surfaces of the cavity receiver, and the Gebhart method is used to simulate the multiple reflections process of solar radiation within the cavity. This integrated simulation method not only reveals the cavity effect on receiver performance but also provides real-time simulation results. Based on this method, the reflection loss of the cavity receiver and solar flux distributions are discussed in detail. The results indicate that the cavity effect can significantly reduce the reflection loss and homogenize the concentrated solar energy distributed on interior surfaces to some extent. Moreover, the surface absorptivity has less effect on the reflection loss when cavity effect is considered. The cavity effect on homogenizing solar flux distributions is greater with lower surface absorptivity. In addition, although the concentrated solar energy is distributed on the cavity aperture with similar shapes at different times, the shape of the solar flux distribution on interior surfaces varies greatly with time. (C) 2015 Elsevier Ltd. All rights reserved.