Objective To observe the effect of indwelling transanal tube on prevention of anastomotic leakage after congenital megacolon radical correction. Methods One hundred and three children who had underwent congenital megacolon radical correction were divided into indwelling group (53 cases) and no indwelling group (50 cases) according to the operation method, and the operation condition and incidence of complications was compared between 2 groups. Results There were no statistical differences in operation time, amount of bleeding during operation and incidence of other complications (pelvic infection and disruption of wound) (P>0.05). The incidence of anastomotic leakage in indwelling group was significantly lower than that in no indwelling group: 0 vs. 12.0% (6/50), and there was statistical difference (P<0.05). Conclusions Indwelling transanal tube for drainage and decompression is effective in preventing the anastomotic leakage after congenital megacolon radical correction, and it has high effectivity and safety.