<p>The large-sized agglomerates formed by molten aluminium particles at the combustion surface significantly affect the combustion performance of aluminium-based propellants. In this investigation, the combustion characteristics and plume signatures of reduced smoke propellants with various fluorides (LiF, MgF₂, and PTFE) were investigated using a laser ignition system and a micro-sized engine combustion system. After adding fluorides, the ignition stage and overall combustion time of the propellants were shortened, and the combustion stabilisation was advanced. Due to the effect of fluorides in corroding the Al₂O₃ shell, the phenomenon of agglomeration was effectively suppressed, and the particle size of condensed-phase combustion products was reduced. And the combustion efficiency was improved, among which the combustion efficiency of the propellant modified with MgF₂ was increased to 91.7%. MgF₂ is the most effective for improving the ignition and combustion of reduced smoke propellants, attributed to the more easily broken Mg–F bond, followed by PTFE and LiF. However, MgF₂ has no effect in reducing smoke in the plume, while LiF increased the plume transmittance by 10.9 and 2.6% at 5 and 10 cm away from the nozzle, respectively. This work provides data support for the selection of fluoride additives for reduced smoke propellants to improve their combustion and plume characteristics.</p>