Objective To analyze the clinical efficacy and relative influence factors of self-expanding metallic stents (SEMS) in treating colorectal cancer obstruction.Methods Information of 47 patients received SEMS to treat colorectal cancer obstruction from Mar.2012 to Dec.2017 in Beijing Haidian Hospital were collected,who were then followed up in outpatient or by telephone.Effective rate,survival rate and complications were recorded and calculated by the software of SPSS 17.0.Chi-square test was used to analyze relative influence factors.Results Results shown that the clinical efficacy was 100％ (47/47).Patients' 30-day survival rate and 6-month survival rate were 87.2％ (41/47) and 68.1％ (32/47),respectively.After surgery,2 patients presented with perforation,3 patients presented with migration and 5 patients presented with reobstruction.Clinical stage of tumor and stent length were related with complications and survival.Therein,complications presented more in patients with advanced cancer.And the longer stent length,the higher mortality.Conclusions Clinical stage of tumor and stent length maybe risk factors of complications and survival of patients after SEMS surgery of colorectal cancer obstruction.