In this study, a new facile preparation method of nanocomposites consisting of graphene oxide and manganese dioxide nanowires(GO/MnO2 NWs) was developed. The morphology, structure and composition of the resulted products were characterized by transmission electron microscopy, X-ray diffraction and N2 adsorption and desorption. The GO/MnO2 nanocomposite was used as an electrode material for non-enzymatic determination of hydrogen peroxide. The proposed sensor exhibits excellent electrocatalytic performance for the determination of hydrogen peroxide in phosphate buffer solution(PBS, pH7) at an applied potential of 0.75 V. The non-enzymatic biosensor for determination of hydrogen peroxide displayed a wide linear range of 4.90 mmol L^-1–4.50 mmol L^-1with a correlation coefficient of 0.9992, a low detection limit of 0.48 mmol L^-1 and a high sensitivity of 191.22μA(mmol L^-1)^-1cm^-2(signal/noise, S/N = 3). Moreover, the non-enzymatic biosensor shows an excellent selectivity.