In the present investigation, an efficient heterogeneous catalyst system made of polyaniline derived polymer (Poly [anthranilic acid]-[N-(1′,3′-phenylenediamino) −3-butane sulfonate]), and iron oxide nanoparticles (Fe₃O₄ NPs), is presented. Firstly, this novel-designed catalytic system (Fe₃O₄@Polyaniline-SO₃H) has been fabricated via a convenience method and magnetized via an in situ process. The as-prepared solid acid catalyst was also carefully analyzed by Fourier transfer infrared spectroscopy (FTIR) and energy-dispersive X-ray spectroscopy (EDX). It has been suitably applied for the one-pot multicomponent synthesis of acridinediones as an important class of heterocyclic compounds. As the first and foremost advantage of this catalytic system, this can be referred to that the (Fe₃O₄@Polyaniline-SO₃H) is magnetically separated from the reaction mixture through their high paramagnetic behavior. The main attractive characteristics of the presented green protocol are very short reaction times, excellent yields, and the avoidance of hazardous or toxic reagents and solvents. Easy separation, high reusability, cost-effective and mild catalyst are important advantages of the new catalyst in comparison to other catalysts for the synthesis of acridinedione derivatives via one-pot four-component reaction.