Objective To investigate the effect of timing of neostigmine antagonizing cisatracurium on residual muscle relaxation and early lung function in patients underwent laparoscopic radical resection of colorectal cancer．Methods February 2021 to September 2022,194 patients who underwent radical colon cancer surgery in our hospital were selected as the research subjects．The patients were randomly divided into a blank control group and an experimental group using a random number table method．Then,combined with the train-of-four（TOF）ratios observed during neostigmine treatment,the experimental group patients were divided into experimental group A（TOF≤0.1）,experimental group B（0.10.8）．The residual muscle relaxation and lung function between groups were compared．Results Before intubation,the TOF ratio of patients in experimental group A was lower than that of other groups（P<0.01）,while the TOF ratio of patients in the blank control group was higher than that of other groups（P<0.01）．There was no significant difference in the observation time between the blank control group and the experimental group A~E in the postanesthesia care unit（P>0.01）．The muscle relaxation recovery index of patients in experimental group A was lower than that of other groups（P<0.01）,while the muscle relaxation recovery index of patients in the blank control group was higher than that of other groups（P<0.01）．There were no significant differences in force expiratory volume in one second（FEV1）,forced Vital capacity（FVC）and FEV1/FVC between groups before intubation,0.5 h after extubation and 24 h after extubation（P>0.05）．Conclusions Administration of neostigmine after radical surgery for colorectal cancer can accelerate muscle relaxation recovery,but it will not affect the residence time of the postanesthesia care unit and lung function levels．