Al-based amorphous alloys have large potentiality in marine equipment protection due to their high strength-to-mass ratio and great corrosion and wear resistance. However, Al-based alloys are prone to precipitate α-Al crystals during the formation process, which could greatly weaken the glass-forming ability. The glass-forming ability was hard to evaluate because of the low glass-forming ability for Al-based alloys. In order to overcome the difficulty, a simple method to evaluate glass formation ability was supported: the first, ribbons were prepared by means of a single-roll ribbon spinning method under the same conditions; the second, amorphous contents of ribbons were calculated by fitting the XRD patterns; the higher the amorphous content is, the higher the glass-forming ability is. The influence of Ni and Zr on the glass-forming ability of AlNiZr alloys was presented based on the amorphous contents of ribbons with different compositions which were Al100-x-yNixZry (x=5, 10 and 15; y=3, 6 and 9), respectively. The result showed that as the content of Ni increased, glass forms Capacity increased; with the increase of Zr content, glass-forming ability decreased. Subsequently, it was determined that the Zr content was 3 at.%, and the Ni content was further increased to 20 at.% and 25 at.%. It was found that the glass-forming ability of the alloy was reduced. Finally, the optimized alloy composition was considered as Al82Ni15Zr3.