Objective. To confirm the effect and safety of Xiao’er Biantong (XEBT) granules for treating chronic constipation in children. Methods. This randomized, double‐blind, multicenter study enrolled 480 children with age of 1–14 years who had FC. All of them were randomly assigned to receive either XEBT granules or its placebo in the ratio of 3 : 1. The primary efficacy outcome was the frequency of spontaneous bowel movements (SBM) for 14 days, and secondary outcomes were effectual time, score of main symptoms, effect of constipation, disappearance rate of accompanying symptoms, and recurrence rate. We also observed the adverse event (AE) and adverse drug reaction (ADR) to evaluate safety. Results. The sociodemographic characteristics and efficiency data were comparable in the two groups at baseline. The mean values of SBM for 14 days were 8.89 and 5.63 in the XEBT group and the placebo group, respectively, and there were 86.87% and 30.91% subjects in two groups up to SBM ≥ 3/week, respectively. There were significant differences between the two groups. The effects in the XEBT group on median effectual time of defecation, main symptom score, disappearance rate of symptoms, and the differences were significant. The conclusions based on full analysis set (FAS) and per protocol set (PPS) were consistent. Nine AEs were reported, of which 7 were in the XEBT group (2.02%) while 2 were in the placebo group (1.77%). There were no significant differences in the occurrence rate of AE and ADR between the two groups. Conclusions. Xiao’er Biantong granules have superior efficacy compared to the placebo for the treatment of functional constipation in children and are well tolerated.