To observe the whitening effect of tooth whitening gel decolorization treatment for tetracycline stained tooth and dental fluorosis. Methods A total of 54 patients with tetracycline stained tooth and dental fluorosis treated in our hospital from March 2022 to March 2023 were selected as the research objects. They were divided into control group and observation group by random number table method, with 27 patients in each group. The control group was treated with traditional decolorization, and the observation group was treated with tooth whitening gel decolorization. The treatment effect, tooth appearance score, aesthetic satisfaction, sensitive duration and incidence of adverse reactions were compared between the two groups. Results The total effective rate of treatment in the observation group was 96.30%, which was higher than 81.48% in the control group (P <0.05). After treatment, the dental appearance score of the observation group was higher than that of the control group (P <0.05). The aesthetic satisfaction of the observation group was 100.00%, which was higher than 88.89% of the control group (P <0.05). The duration of sensitivity in the observation group was shorter than that in the control group (P <0.05). There was no significant difference in the incidence of adverse reactions between the observation group and the control group (P >0.05). Conclusion The whitening effect of tooth whitening glue in the treatment of tetracycline stained tooth and dental fluorosis is definite, which can improve the appearance of teeth and shorten the sensitive time, and the patients are more satisfied with the treatment.