Objective To explore the effect of nursing intervention on the oral hygiene of vagrant patients with mental problems.Methods Toally 80 vagrant patients with mental problems were saved and treated with oral health care intervention for a period of three months.The pre-intervention effects were prepared with the post-intervention ones in terms of tooth brushing,oral health and periodontal disease related symptoms intervention.Results Before intervention,the rate of tooth brushing was significantly higher and the rate of periodontal disease related symptoms significantly lower than that before intervention (P＜0.05).The scores on physical function limitation,pain and discomfort,psychological discomfort,weakened ability in independent living and the total score after intervention were all significantly lowered as compared to the pre-intervention.Conclusion Oral nursing intervention can improve oral hygiene and oral health of vagrant patients with mental diseases.