In order to overcome the problems of easy agglomeration， easy oxidation and poor combustion performance of nano-boron powder， fiuorine rubber（F₂₆₀₂） was used as binder.Nano-boron/F₂₆₀₂ composite microspheres with different process parameterswere prepared by electrostatic spray method.The perparationtechnology of composite microspheres were optimized by orthogonal experiment， and the best preparation conditions for uniform particle size and rounded morphology of microspheres were been found. The morphology， structure and thermal properties of the composite microspheres were characterized by scanning electron microscopy， X-ray diffraction， infrared spectroscopy， and thermogravimetry. The results show that the optimum preparation conditions were as follows： solution concentration 7%， the content of F₂₆₀₂ to boron power 3.5%， the injection rate 1 mL·h^-1 and the injection voltage 18 kV. The prepared nano-boron /F₂₆₀₂ composite microspheres have good dispersion， and the serious agglomeration of nano-boron powder is improved. The boric acid peak on the surface of boron nanoparticles did not appear on the composite microspheres， indicating that the composite microspheres prepared by electrostatic spraying can effectively prevent the surface oxidation of boron nanoparticles. Compared with the raw boron powder， the weight gain of the composite microspheres increased by 22.98%， and the reaction degree with oxygen was deeper， and the boron energy release was more complete.