Electroless plating was used to deposit Ni-P films on quartz optical fiber surface. The optimal bath compositions and operation conditions were determined by orthogonal experiment: nickel sulfate 0.133 mol/L, sodium hypophosphite 0.30 mol/L, propionic acid 0.268 mol/L, boric acid 0.452 mol/L, pH 5.0 and temperature 84°C. Stereomicroscope, scanning electron microscope, X-ray diffractometer, energy spectrometer and thermal shock test were used to characterize the morphologies, structures, compositions and adhesion of the Ni-P films. The results showed that a Ni-P film with good smoothness and adhesion as well as low resistivity was fabricated. The kinetic model was established and proven by the experiments.