In the present work, a novel amperometric sensor of 6-benzylaminopurine (6-BA) was developed, which based on Pt nanoparticles/ordered mesoporous carbons (Pt/OMCs) modified glass carbon (GC) electrode. The mechanisms for 6-BA oxidation at the Pt/OMCs electrode were investigated, which is an adsorption-controlled process and the standard rate constant of electrochemical reaction (ks) is 0.51s−1. The 6-BAH+ and neutral 6-BA molecule may be the electroactive substances in the pH range of 2.0–6.0 and 6.0–11.0, respectively. The Pt/OMCs electrode shows a wider linear range (0.05 to 24 μM) and low detection limit (5 nM) for detecting 6-BA. Compared with the other modified electrode, the Pt/OMCs nanocomposites exhibit a good electrocatalytic activity, excellent stability and repeatability towards 6-BA. Moreover, it was successfully applied to the determination of 6-BA in real samples.