Abstract: Continuous alumina fiber(Al₂O_3f), known for their high strength, corrosion resistance and high-temperature tolerance, holds significant strategic importance for the enhancement of China’s national defense equipment and major economic industries. It is widely used as a reinforcing phase in metal matrix composites（MMCs）. However, the poor wettability between alumina fiber and metal matrix limits the improvement of the properties of metal matrix composites. The application of a metal coating on the surface of alumina fiber can effectively improve the wettability between Al₂O_3fand the matrix, and endows it with special electrical and magnetic properties, which broadens the application field of alumina fiber. In this study, a uniform and complete nickel coating was successfully prepared on the surface of continuous alumina fiber by electroless plating. The surface morphology and elemental composition of nickel-plated fiber were analyzed by scanning electron microscopy and X-ray energy dispersive spectrometer. Combined with the weight gain rate and unit resistance value of the plated fiber, the effects of various factors on the quality of nickel coating were compared and analyzed. The results show that the coating fiber has an obvious core-shell structure(Al₂O_3f@Ni), with an outer layer of intact metallic nickel plating and an inner core of Al₂O_3f. Under the experimental conditions, the best quality metal plating is achieved with nickel sulfate at 35 g/L, sodium hypophosphite at 25 g/L, sodium citrate at 30 g/L, ammonium chloride at 20 g/L, and the system temperature 75℃. The weight gain rate is as high as 30 wt%, and the unit resistance is as low as 0.8 Ω/cm.