ObjectiveTo investigate the variation regularity about volume of drainage after initial thyroidectomy, and to find out the time points of safety extubation and the time points of risk extubation. MethodsBetween September 2013 and April 2014, the clinical date of 71 cases of thyroid tumor who underwent thyroidectomy were prospectively analyzed and completely random designed. The patients were indwelling drain after thyroidectomy, the volume of drainage liquid were registered at each point of time in period of 48 hours after operation and analyzed its the variation regularity. ResultsThe volume of drainage fluid in 48 h after operation was gradually decreased in 71 patients. The reduce speed of volume of drainage fluid in the 12 h after operation was faster, then was significantly slower, and gradually stabilized. The amount of the drainage fluid reached the peak in 2 h after operation in 22 cases, and then gradually decreased and reached the stabilization. ConclusionsThe 2 hours after thyroidectomy is the risk drainage removing time when is relatively safe. The 12 hours after thyroidectomy is the safety drainage removing time, after that there is no longer any meaning to keep drainage tube.