Objective: To explore the effect of micturition diary on the urine volume of patients with urinary calculi and the prognosis of residual stones. Methods: From March to June 2019, 98 patients with urinary calculi admitted to the Urology Department of People’s Hospital of Guangxi Zhuang Autonomous Region were selected. There were 50 cases in the control group and 48 cases in the observation group. The control group was instructed to consume 2 000~2 500 mL of liquid daily by oral and paper prescriptions. The observation group was instructed to adjust fluid intake by micturition diary on the basis of routine instruction. After discharge, the patients in observation group continued to adjust fluid intake with a micturition diary. The 24 h urine volume of the two groups was compared one day before discharge, one month after discharge and one year after discharge. The patients in the two groups were compared for the balance of urination on the day before discharge and the prognosis of residual stone one year later. Results: The 24-hour urine volume of the observation group was (1.98±0.91) L, (1.95±0.69) L, (1.94±0.73) at 24 h before discharge, 1 month after discharge and 1 year after discharge respectively, which was higher than that of the control group (1.56±0.78) L, (1.42±0.61) L, (1.45±0.53) L. For observation group, the number of cases with balanced urination was higher than that of the control group, the incidence of residual stone growth was lower than that of the control group, and the incidence of residual stone excretion was higher than that of the control group. Conclusion: The application of micturition diary can increase the urine volume of patients with urinary calculi, promote the balanced fluid intake of patients, and improve the prognosis of patients with residual stones.