Electrochemical behaviors of thiocyanate on three carbon nanotubes (CNTs) composites modified glass carbon electrode (GCE) were studied. The modified electrodes were prepared with CNTs suspended in aqueous solutions of chitosan (CHT), poly(diallyldimethylammonium chloride) (PDDA) and cetyltrimethylammonium bromide (CTAB), respectively. The results indicated that CNTs‐CTAB enhanced the voltammetric response of thiocyanate more remarkably than other two CNTs composites. Then, the voltammetric behaviors of thiocyanate on CNTs‐CTAB/GCE were investigated systematically to develop an electrochemical sensor for thiocyanate determination. The solution pH, supporting electrolyte, amount of CNTs‐CTAB suspension, and accumulation time were optimized. Under optimum conditions, the anodic peak current on CNTs‐CTAB/GCE increased linearly with increasing the thiocyanate concentration from 5.0×10−6 to 1.0×10−4 mol L−1. The proposed CNTs‐CTAB/GCE was demonstrated to provide a fast and low‐cost approach to monitoring the adsorptive removal of thiocyanate with layered double hydrotalcite (LDH).