Within the scope of this study, the removal of methylene blue (MB) dye from aqueous solution with SiNH2@FeNP nanocomposite, which was synthesised by green synthesis method using liquorice root (Glycyrrhiza Glabra) extract, was investigated by applying Box-Behnken experimental design method. With this newly synthesised material, solution pH value, adsorbent dosage and initial dye concentration parameters affecting the adsorption process in methylene blue removal from aqueous solutions were investigated. FTIR, SEM, BET and XRD techniques were applied to characterise the structure of the obtained SiNH2@FeNP nanocomposite. According to the data obtained from the experimental design results, in order to obtain approximately 87% methylene blue dye removal efficiency, pH, initial methylene blue concentration and adsorbent dosage values should be kept constant at 8.8, 35.8 and 3.38 g L-1, respectively. Meanwhile, to achieve an MB adsorption of 22 mg g(-1), the initial adsorbent dose and pH should be kept at 0.5 g l(-1) and 10, respectively. SiNH2@FeNP nanocomposite produced by the green synthesis method is an environmentally friendly and effective adsorbent.