With the concept of green industry, the development of leather tannery chemicals towards sustainability has become an inevitable trend. As a natural biomass macromolecule material, chitosan has great potential in the application of leather tannery chemicals because of its safety, non-toxicity, environmental friendliness, biodegradability, and antibacterial properties. This paper reviews the current status of research in the tanning industry, and introduced the application prospects of chitosan in various leather-making processes (tanning, fatliquoring, dyeing, wastewater treatment, etc.). Finally, the development trend of chitosan in clean leather making was prospected.