Objective To explore the effect of microabrasion combined with cold light whitening in patients with mild to moderate enamel hypoplasia. Methods A total of 90 patients with mild to moderate enamel hypoplasia admitted to Beijing Nuclear Industry Hospital from January 2024 to February 2025 were selected, and they were divided into the control group (75 affected teeth) and the observation group (70 affected teeth) by the random number table method, with 45 patients in each group. The control group was treated with conventional microabrasion, and the observation group was treated with microabrasion combined with cold light whitening. The treatment effect, microhardness and surface roughness of affected teeth, and satisfaction were compared between the two groups. Results The total effective rate of the observation group (93.33%) was higher than that of the control group (73.33%) (P <0.05). The microhardness of affected teeth in the two groups at 3 months after treatment was higher than that before treatment, and that in the observation group was higher than that in the control group (P <0.05). The surface roughness of affected teeth in the two groups at 3 months after treatment was lower than that before treatment, and that in the observation group was lower than that in the control group (P <0.05). The satisfaction rate of the observation group (91.11%) was higher than that of the control group (66.67%) (P <0.05). Conclusion Microabrasion combined with cold light whitening has a definite effect in patients with mild to moderate enamel hypoplasia. It can improve the treatment effect, enhance the hardness of affected teeth and reduce tooth surface roughness, which is conducive to improving patient satisfaction. It is worthy of clinical application.