Objective To evaluate the process risk of the implementation of prevention and control measures for surgical site infection (SSI) after colorectal surgery, and explore the application effect of failure mode and effects analysis (FMEA) based on action priority. Methods FMEA based on action priority was adopted to evaluate the whole process of the implementation of prevention and control measures for SSI after colorectal surgery. Prioritization ranking was conducted according to whether optimized measures were taken. Standard-reaching rate of comp-liance to SSI prevention and control measures as well as SSI incidence before and after the implementation of FMEA were compared. Results After evaluation, there were 7 high-priority and 22 medium-priority prevention and control measures for SSI. The control of medium-priority measures was strengthened, with a focus on developing further preventive and detectable measures for high-priority measures. The re-evaluation results after improvement showed that 7 high-priority measures have been downgraded to medium priority, and 16 medium-priority measures have been downgraded to low priority. Standard-reaching rate of compliance to SSI prevention and control measures increased from 77.15% (2 566/3 326) to 92.47% (3 096/3 348), and SSI incidence decreased from 6.04% (58/960) to 2.54% (60/2 364). Conclusion Application of FMEA based on action priority can effectively evaluate the risk of prevention and control process of SSI after colorectal surgery, and adopting preventive risk control measures according to the current situation can reduce the incidence of SSI after colorectal surgery.