The main objective of the work is to develop numerical method for improving design/simulation tools and answering to specific questions related with heat and mass transfer inside a pressurized volumetric receiver (PVR), providing fundamental basis to design new receivers for the DAHAN project later. In this paper, an idealized three-dimensional axialsymmetric computation model of a PVR with a secondary concentrator (SC) which is almost intrinsic axial symmetry is presented firstly by some simplification assumptions. A new designing method and homemade unified code of the Monte Carlo Ray-Trace (MCRT) Method for numerical investigations on solar concentrating and collecting characteristics of the PVR is proposed. Then the proposed method and code is applied to simulate and analyze the involuted photo-thermal conversion process in the PVR, covering solar concentrating, collecting and transferring process of solar energy. Solar radiation in participating medium and/or non-participating medium can be taken into account simultaneously or dividedly in the simulation. The non-uniform solar energy flux density distribution in the receiver is also calculated, which can be used to investigate the complex coupled heat transfer process of the system for further study later. (C) 2012 Elsevier Ltd. All rights reserved.