BACKGROUND: Dental pulpitis significantly impacts oral function and quality of life. Treatments like direct pulp capping aim to preserve pulp vitality. OBJECTIVE: This study aims to investigate the application value of Nd:YAG laser irradiation in preserving pulp vitality in children with caries-induced pulpitis. METHODS: This study, conducted from June 2019 to June 2023, included 89 children undergoing pulp vitality preservation treatment for caries-induced pulpitis. The children were divided into two groups using sealed envelopes: 44 in the control group received pulp capping treatment, while the study group received Nd:YAG laser-assisted pulp capping treatment. The efficacy, oral indicators, oral function, changes in root apex diameter and root length, changes in gingival crevicular fluid inflammatory factors, and incidence of complications were compared between the two groups before and 3 months after treatment. RESULTS: The total effective rates were 97.78% in the study group and 95.45% in the control group, with no significant difference between the groups (p> 0.05). Before treatment, there were no differences in gingival index, plaque index, and probing bleeding index between the groups (p> 0.05). After treatment, both groups showed decreased periodontal indexes compared to before treatment, with the study group showing lower values than the control group (p< 0.05). Chewing and biting function scores were similar between the groups before and after treatment (p> 0.05), but both groups showed decreased scores after treatment (p< 0.05). The study group had a higher percentage decrease in root apex diameter and a greater increase in root length compared to the control group (p< 0.05). During treatment, one case of tooth discoloration occurred in the study group (2.27%), while the control group had two cases of tooth discoloration and one case of secondary caries, resulting in a complication rate of 6.67%. There was no significant difference in the incidence of complications between the groups (p> 0.05). CONCLUSION: Nd:YAG laser irradiation effectively preserves pulp vitality in children with caries-induced pulpitis, improving periodontal health, reducing root apex diameter, and increasing root length with high safety.