Abstract: A three-dimensional porous nickel molybdenum sulfide nanoflowers supported on carbon nanotubes (CNT) composite materials (NiMoS@CNT) was prepared. The morphology and structure of the synthesized materials were characterized by scanning electron microscopy and X-ray diffraction. The cyclic voltammetry and chronoamperometry were used to study the electrochemical catalytic performance of the prepared materials. Based on the excellent electrocatalytic performance of NiMoS@CNT for hydrogen peroxide, a sandwich electrochemical sensor for detecting brain natriuretic peptide (BNP) was constructed. Under the optimal conditions, the current response intensity and the logarithm of mass concentration of brain natriuretic peptide was linear in the range of 0.20~20 ng/mL. The immunosensor has a high sensitivity, selectivity and stability, and can be used for the detection of BNP in actual samples.