With high energy density and self-sustained combustion under the condition of small size, metastable intermolecular composites (MIC) array has potential value in the application of intergrated initiating explosive devices. In the current study, highly ordered MoO₃ nanobelts array was prepared by a flame method. The possible factors which may influence the morphology of MoO₃ nanobelts, such as different substrate, growing time, and the flame source, were also studied. The optimal conditions for growing MoO₃ nanobelts array were obtained as follows: utilizing Si as the substrate and CH₄ gas as the flame source with the growing time of 5 min.The as-synthesized MoO₃ nanobelts possess a thickness of ~5 nm, a width of ~5 μ m, and a length larger than 10 μ m. And then MIC-Al/MoO₃ array was prepared by aluminum plating on the surface of MoO₃ nanobelts via the magnetron sputtering and thermal evaporation method respectively. The results show that MIC-Al/MoO₃ fabricated by thermal evaporation method has higher heat release (3276 J·g^-1) compared that by the magnetron sputtering method with the same aluminum film thickness.