In order to impart self-cleaning and anti-fouling properties to silk fabric, firstly, polydopamine (PDA) was prepared by the polymerization of dopamine (DA) under CuSO4/H2O2 oxidation system and was deposited on the silk surface, and then the fabric was further superhydrophobically functionalized by dodecyltrimethoxysilane (DTMS) modified nano-TiO2. The FTIR, SEM, XPS, water contact angle measuring instruments were used to characterize the chemical composition, surface microstructure, and hydrophobic properties of silk fabric before and after modification. The self-cleaning and anti-fouling properties, self-repairing of hydrophobicity and UV resistance also were tested. The results showed that the PDA/DTMS-nano TiO2 modified silk fabric surface constructed uniformly micro and nano structure, as well as its surface energy reduced. The static contact angle of modified fabric was 156°, the rolling angle was 5°, and the UV protection factor was 75.81, so it had good anti-fouling self-cleaning ability and UV resistance. Its permeability slight decreased. When after 10 etching-repair cycles of O2 plasma or 1200 mechanical wear-repair cycles, the hydrophobic repair rate of the PDA/DTMS-nano TiO2 modified fabric was greater than 96%, and the self-healing effect of environmental damage resistance was obvious. In addition, after 25 washes, the contact angle of the modified silk fabric was 151° and the UPF value was 49.5, which still had relatively excellent washing fastness.