Objective To analyze the effect of microneedle introduction of sodium hyaluronate gel containing ergothioneine on skin barrier function in patients with sun-induced facial hyperpigmentation. Methods A total of 60 patients with sun-induced facial hyperpigmentation admitted to Suining Central Hospital from December 2024 to September 2025 were selected, and they were divided into the control group and the study group by the random number table method, with 30 patients in each group. The control group was treated with microneedle introduction of medical sodium hyaluronate liquid dressing, and the study group was treated with microneedle introduction of sodium hyaluronate gel containing ergothioneine. The clinical efficacy, skin barrier function (transepidermal water loss, stratum cornerum hydration, melanin value), satisfaction and adverse reaction rate were compared between the two groups. Results The total effective rate of treatment in the study group (93.33%) was higher than that in the control group (73.33%), and the difference was statistically signiffcant (P<0.05). At 28 days after the last treatment, the stratum cornerum hydration in the study group was higher than that in the control group and the difference was statistically signiffcant (P<0.05). At 28 days after the last treatment, the transepidermal water loss and melanin value in the study group were lower than those in the control group, and the differences were statistically significant (P<0.05). The satisfaction rate in the study group (86.67%) was higher than that in the control group (63.33%), and the difference was statistically signiffcant (P<0.05). There was no statistically signiffcant difference in the incidence of adverse reactions between the two groups (P>0.05). Conclusion In patients with sun-induced facial hyperpigmentation, the application of sodium hyaluronate gel containing ergothioneine can effectively improve clinical efffcacy and satisfaction, improve skin barrier function, without increasing adverse reactions, which is worthy of clinical application.