Objective To study the clinical effect of the secondary prevention of chronic ankle instability (CAI) for nursing staff. Methods From September 2014 to January 2015, we screened 100 nurse with functional ankle instability in Shandong Provincial Hospital. The subjects were divided into the intervention group (n=51) and the control group (n=49) by random number table. The nurses of intervention group accepted measures of the secondary prevention, including bundle health education, bracing and rehabilitation, while the nurses of control group received only routine health education. Before intervention and 4 months later, we evaluated the ankle instability by Chinese version Cumberland ankle instability tool (CAIT) in two groups and compared the intervention effects and relevant knowledge of the two groups. Results Before the intervention, the CAIT score of intervention group was (19.0±4.8), and was (28.2±3.0) after intervention (t=9.210, P 0.05); after intervention, the difference of two groups had statistical significance (t=9.317, P<0.05). Conclusions The secondary prevention of CAI can improve CAI nurse staff′s ankle stability and the recognition level of CAI prevention knowledge, and promote the clinical symptom prevention effectively, so it has significance for the improvement of nurse′s ankle function. Key words: Nurses; Ankle; Instability; Secondary prevention