Objective To analyze the effect of nursing intervention based on the Health Action Process Approach (HAPA) on periodontal health indicators in patients after immediate implantation for traumatic tooth loss. Methods A total of 80 patients who underwent immediate implantation for traumatic tooth loss in Guiyang Hospital of Stomatology from May 2023 to May 2025 were selected, and they were divided into the control group and the observation group by the random number table method, with 40 patients in each group. The control group received conventional nursing, and the observation group received nursing intervention based on HAPA on the basis of the control group. The periodontal health indicators, peri-implant bone resorption, compliance, nursing satisfaction and self-efficacy were compared between the two groups. Results After nursing, the mPLI, mBI, PD and GI in the observation group were lower than those in the control group (P <0.05). The peri-implant bone resorption in the observation group was (0.62±0.18) mm, which was lower than (1.04±0.25) mm in the control group (P <0.05). The compliance rate of the observation group (92.50%) was higher than that of the control group (67.50%) (P <0.05). The nursing satisfaction rate of the observation group (95.00%) was higher than that of the control group (77.50%) (P <0.05). The GSES score of the observation group after nursing was higher than that of the control group (P <0.05). Conclusion The application of nursing intervention based on HAPA can improve periodontal health indicators of patients after immediate implantation for traumatic tooth loss, reduce peri-implant bone resorption, help to improve patients’ compliance and nursing satisfaction, and enhance their self-efficacy.