In order to address the poor solubility of Eucommia ulmoides gum（EUG）caused by its crystallinity，so that its direct use in modified coatings and adhesives，we synthesized hydroxylated Eucommia ulmoides gum（HEUG） by reacting thiol-ethanol with
EUG under 365 nm UV light using thiol-ene click chemistry. This process disrupted the crystallinity and enhances solubility. We investigated the effects of different solvents（water，N，N-dimethylformamide，chloroform），molar ratios of C=C double bonds to thiol groups，and reaction times on the degree of hydroxylation of EUG. Additionally，we studied the impact of hydroxylated EUG on the mechanical properties，flexibility，solvent resistance，adhesion，and self-healing performance of self-healing polyurethane（PU） coatings. The results indicatedthat the modified EUG exhibited excellent solubility in common solvents. The highest degree ofhydroxylation，156 mgKOH/g，was achieved using chloroform as the solvent，a reaction time of 6 hours，and a thiol to C=C double bond molar ratio of 3：1. When HEUG was combined with self-made self-healing polyurethane（DSPU）resin，the optimal addition amount was found to be 5% by mass. At this concentration，the coating demonstrated strong mechanical properties， high elongation，rapid self-healing，high transparency，and overall good performance.