Abstract：Objective To study the clinical effect of preservation of calcium hydroxide paste in the treatment of patients with caries-derived pulpitis. Methods The 94 patients with caries-derived pulpitis in our hospital from June 2018 to June 2019 were selected as research objects. Based on the random number table method, they were divided into control group and research group, with 47 cases in each group. The patients in the control group received zinc oxide clove oil paste vital pulp preservation treatment, and in the study group received calcium hydroxide paste vital pulp preservation treatment. The pain score and the success rate of preservation of marrow were compared between the two groups after treatment. Results After treatment, the pain score in the research group was lower than the control group, the differences in the two groups were statistically significant（t＝13.4946, P＜0.05）; and the pulp preservation success rate was higher than the control group, the differences in the two groups were statistically significant（χ2＝4.0286, P＜0.05）. Conclusion Calcium hydroxide paste vital pulp preservation treatment for patients with caries-derived pulpitis can relieve patients′pain and improve the success rate of pulp preservation, which is worthy of promotion.