〔Abstract〕 Objective To observe the effect of calcium hydroxide preparation in the treatment of dental pulp diseases. Methods A total of 72 patients with dental pulp diseases admitted to our hospital from April 2019 to April 2020 were selected as the research objects, and were divided into control group (36 cases: conventional treatment) and observation group (36 cases: calcium hydroxide preparation treatment) according to the different treatment methods, and the treatment effects of the two groups were compared. Results Compared with before treatment, the gingival sulcus bleeding index and plaque index in 2 groups were decreased after treatment, and the gingival sulcus bleeding index and plaque index in observation group were lower than those in control group, the difference was statistically significant (P < 0.05). The total effective rate (97.22%) in observation group was higher than that in control group (77.78%) 4 weeks after operation, the difference was statistically significant (P < 0.05). The satisfaction of clinical treatment effect in observation group (97.22%) was significantly higher than that in control group (75.00%), the difference was statistically significant (P < 0.05). Conclusion The effect of calcium hydroxide preparation on patients with dental pulp disease is significantly better than conventional treatment.