In order to achieve the purpose of material surface strengthening and protection, Ni-P-Al2O3-PTFE nanocomposite coatings were prepared by jet electrodeposition, and the effect of Al2O3 nanoparticle concentration in the plating solution on the microstructure and mechanical properties of the composite coatings was investigated. The surface morphology, microstructure, wear resistance and elastoplasticity of the composite coatings were characterized by x-ray diffractometer, scanning electron microscope, energy-dispersive spectrometer, friction and wear tester and nanoindenter. The experimental results show that the deposition of Al2O3 nanoparticles can significantly improve the comprehensive properties of the composite coating. When the addition amount of Al2O3 sol in the plating solution is 40 ml/L, the surface morphology of the composite coating is uniform and dense, the content of Al and F elements reaches the maximum value of 1.49 and 0.77 wt.%, the average friction coefficient and wear scar width reach the minimum value of 0.1456 and 131.40 μm, and the elastic recovery ratio (he/hmax) reaches the maximum value of 0.32. At this time, the nanocomposite coating exhibits excellent wear resistance and toughness. The development of this research will have a positive effect in the field of preparation and optimization of nanocomposite coatings.