Objective To study the effect of preoperative urination training combined with restrictive fluid therapy with enhanced recovery after surgery (ERAS) on postoperative urination in total knee arthroplasty (TKA) patients. Methods A total of 150 patients who were conducted the unilateral TKA from March to May 2018 were divided into two groups, the trial group and the control group, with 75 patients in each group. The patients in the control group did not undergo urination training before surgery and were given liberal intravenous fluid therapy on the day of surgery; while the patients in the trial group received urination training before surgery and were given restrictive fluid therapy on the day of surgery. The pre-, intra-, and post-operative infusion volume and the total infusion volume on the day of surgery of the two groups were recorded; and the urination situation, urination time for the first time and the hospital days in the two groups were compared. Results The total infusion volume on the day of surgery in the trial group and the control group was (1 581.40±277.54) and (2 395.00±257.40) mL, respectively. After operation, in the trial group, there were 73 patients with smooth urinating, 2 with smooth urinating after inducing method, and none with urethral catheterization; in the control group, there were 66 patients with smooth urinating, 3 with smooth urinating after inducing method, and 6 with urethral catheterization. The urination time for the first time after operation in the trial group and the control group was (1.85±0.91) and (2.93±1.48) hours after back to the ward, respectively. These differences between the two groups were statistically significant (P<0.05). The hospital stay in the trial group and the control group was (5.86±2.48) and (6.28±1.60) days, respectively, and the difference between the two groups was not statistically significant (P>0.05). Conclusions Preoperative urination training combined with restrictive fluid therapy (the total infusion volume controls in about 1 500 mL on the day of surgery) in the TKA patients after ERAS is good for postoperation urination. It also can reduce the rate of postoperative urinary retention, and enhance rehabilitation.