Diseases of ocular fundus are the leading causes of severe vision impairment or even blindness in patients worldwide, and the medical treatments are seriously limited by the difficulty of therapeutic drugs entering the fundus due to the various physiological barriers. Nano-drug delivery systems, with their nanoscale size and large surface area, can be loaded with therapeutic drugs of different physicochemical properties and modified with various surface active substances, which can not only improve the solubility and penetration of the drugs, but also protect biologic drugs from degradation and improve the biological safety and bioavailability, as well as deliver therapeutic drugs to specific ocular targets. All of these make the therapeutic potential enormous. Currently, more and more studies have been carried out to take advantage of nanomaterials for the treatment of different fundus diseases, including neurodegenerative diseases, fundus neovascularization, endophthalmitis and fundus tumors. This review analyzes the challenges and barriers faced by different routes of drug administration in the treatment of fundus diseases, the physicochemical properties of common nano-drug delivery systems that have been studied in related fields, and further summarizes the progress, advantages, limitations, and future directions of the application of various nano-drug delivery systems for the treatment of ocular fundus diseases in recent years.