Objective To investigate the effect of video-assisted thoracoscopy in the treatment of mediastinal tumors.Methods A total of 82 patients with mediastinal tumor treated in Tiemei General Hospital of Liaoning Health Industry Group from June 2018 to January 2020 were selected as the research subjects and divided into the control group (41 cases) and the experimental group (41 cases) according to random number table method.The control group was treated with conventional thoracotomy, and the experimental group was treated with video-assisted thoracoscopy.The surgical indicators, length of stay, pain, bad mood and total incidence of complications were compared between the two groups.Results The postoperative drainage volume and intraoperative blood loss in the experimental group were less than those in the control group, the operative time and hospitalization time in the experimental group were shorter than those in the control group, the differences were statistically significant (P＜0.05).The scores of self-rating anxiety scale (SAS),self-rating depression scale (SDS) and visual analogue scale (VAS) in the experimental group were lower than those in the control group, and the differences were statistically significant (P＜0.05).The total incidence of postoperative complications in experimental group was lower than that in the control group, and the difference was statistically significant(P＜0.05).Conclusion Video-assisted thoracoscopy can reduce intraoperative blood loss, shorten operation time and hospitalization time, improve bad mood, improve compliance, and reduce postoperative complication rate in patients with mediastinal tumor.The therapeutic effect is clear and can be widely used in clinical practice.