To analyze the CBCT images of patients with different maxillary sinus floor types, and measure the bone thickness and cortical thickness in the alveolar ridge area of the maxillary molars, in order to provide reference for safe implantation of micro-implants in patients with different maxillary sinus floor types. Methods From September 2020 to October 2022, 80 adult patients in the Second Affiliated Hospital of Xinjiang Medical University were selected as the research objects. According to the location of maxillary sinus floor, they were divided into high sinus group and low sinus group, with 40 patients in each group. The bone thickness and cortical thickness at three positions (2 mm, 4 mm, and 6 mm from the crestal alveolar ridge) were measured when implants were inserted at angles of 30°, 45°and 60° between the first and second molars was measured. Results There were statistically significant differences in bone thickness and cortical thickness at different angles of different measurement heights in the zygomatic alveolar ridge area of the maxillary first and second molars between the two groups (P <0.05). The maximum bone thickness of the two groups was located at 2 mm from the alveolar ridge top and the bone surface was 60°, and the maximum cortical thickness was located at 6 mm from the alveolar ridge top and the bone surface was 30°. Conclusion By analyzing measurement data, this study provides clear information about bone density differences among different maxillary sinus floor types when inserting micro-implants safely into the alveolar ridge area between first molar to second molar region during dental implant surgery.