AbstractIn this research, design and synthesis of the magnetic nanoparticle, coated by a silica shell and modified with dicationic ionic liquid are described. The characterization of Fe3O4@SiO2 ⋅ DIL was done by means of techniques such as XRD, FTIR, SEM, EDX, TEM, and TGA. The catalytic activity of Fe3O4@SiO2 ⋅ DIL as a new nanocatalyst was tested in the one‐pot tree‐component synthesis of 1,8‐dioxodecahydroacridines. To achieve higher yield of products, factors such as reaction temperature, reaction time, the amount of nanocatalyst and solvent were studied, and the optimized conditions were investigated. The results indicated that the reaction time for aromatic aldehydes bearing substituent at para position is shorter and higher yields of products were obtained with these substrates. Short reaction time, high yield of products, easy purification and easy recoverable catalyst without significantly loss of its activity are the main advantages of the process presented. The results clearly showed that the existing catalytic system could be eco‐friendly and economical to carry out this reaction.