There is growing interest in combustion-driven thermophotovolataic (TPV) power generation. Previous investigations have shown that inadequate conversion of fuel energy to photon-convertible radiation restrained combustion-driven TPV power systems from achieving high efficiency. In this paper, A TPV power system integrating a composite radiant burner and cells with different low bandgaps was proposed and constructed. The composite radiant burner consists of two thermal radiators in tandem. They emit two streams of radiation. GaSb cells and InGaAsSb cells were installed in the TPV power system, and were illuminated by the two radiators, respectively. The radiations were matched correspondingly to the sensitivities of GaSb and InGaAsSb cells. The combustion performance of the composite radiant burner and the electric output characteristics of the TPV cells in the integrated natural gas-fired TPV system were investigated under various conditions. The proposed cascaded utilization of heat released during the combustion and the effective thermal management successfully increased the TPV system efficiency. Crown Copyright (C) 2017 Published by Elsevier Ltd. All rights reserved.