Objective To investigate the preventive effect of systematic nursing on postoperative myasthenic crisis in patients with giant thymomas.Methods A total of 64 eligible patients with giant thymomas who underwent surgical treatment in our hospital from January 2020 to March 2022 were selected and divided into groups according to the random number table method,with 32 cases in each group.Patients in the control group were given routine nursing,while those in the observation group were given systematic nursing.Intervention outcomes were compared between groups.Results The ventilator use time,ICU stay time and average hospital stay in the observation group were significantly shorter than those of the control group(P<0.05).After interventions,the total compliance rate in the observation group was significantly higher than that of the control group(93.75%vs 84.38%,P<0.05).The incidence of myasthenic crisis and other complications in the observation group was significantly lower than that of the control group(P<0.05)The total satisfaction of the observation group was significantly higher than that of the control group(93.75%vs 75.00%,P<0.05).Conclusion The implementation of systematic nursing for patients with giant thymomas can strengthen the prevention of postoperative myasthenic crisis and related complications,and improve a number of clinical indicators and satisfaction.