Objective:To study the effect of mindfulness-based training intervention on clinical efficacy in patients with nitrous oxide(laughing gas) addiction.Methods:From June 2019 to June 2020, sixty-six patients with nitrous oxide addiction in Beijing Gaoxin Hospital were selected and randomly divided into experimental group( n=33) and control group( n=33). The control group received Taijiquan training and physical training, while the experimental group added mindfulness-based training intervention on the basis of Taijiquan training and physical training.Symptom checklist 90 (SCL-90) scores and visual analog scales (VAS) craving scores were compared between the two groups at admission and 8 weeks after treatment.SPSS 22.0 software was used for statistical analysis.Independent sample t test and paired sample t test were used to compare the differences between groups and within groups. Results:(1)Before treatment, there were no significant differences in subscale scores of SCL-90 between the two groups except for depression factor((2.45±0.86), (2.03±0.46), t=2.474, P<0.05). After treatment, the subscale scores of somatization((1.38±0.35), (1.68±0.34), t=-3.656, P<0.05), phobic anxiety((1.49±0.37), (1.81±0.30), t=-3.993, P<0.05), paranoid ideation((1.50±0.47), (1.88±0.31), t=-3.898, P<0.05) and psychotism((1.34±0.54), (1.55±0.27), t=-3.094, P<0.05) of SCL-90 in the experimental group were significantly lower than those in the control group.(2)Before treatment, there was no significant difference in VAS craving score between the two groups( t=0.857, P=0.395). After treatment, the score of VAS in the experimental group was significantly lower than that in the control group( t=27.427, P<0.05). Conclusion:Mindfulness training intervention can effectively improve the clinical symptoms of patients with nitrous oxide addiction, which is worthy of clinical application.