A lot of attention has been given to incorporation of carbon nanomaterials (CNMs) including carbon nanotubes (CNTs) in ammonium perchlorate (APC) based solid propellants to enhance their final performance. (CNTs) has many applications in the energetic material field due to its large surface area and surface energy. This study reports on catalysed ammonium perchlorate (APC) by multi wall carbon nanotube (MWCNT). MWCNTs were successively encapsulated with APC particles by using modified fast-crash solvent–antisolvent technique and characterized by scanning electron microscope (SEM) and Energy dispersive X-ray spectrometer (EDX). The catalytic performance of MWCNT on the thermal behaviour of ammonium perchlorate (APC) was analysed using differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Interestingly, the effect of MWCNTs on the thermal decomposition of APC where the results showed that encapsulated APC with 1% MWCNT show significant decreasing in the high temperature of decomposition APC from 452.8°C to 390.1°C and MWCNTs giving an increase in total releasing heat of APC by 130 %. The results confirmed that MWCNTs are a novel catalysing agent on the thermal degradation of ammonium perchlorate which has a direct impact on the burning behaviour, performance and combustion regime of the solid rocket propellants.