Background: Self-expandable metal stent (SEMS) placement with an emergency colonoscope has been gradually applied to treat colorectal carcinoma with intestinal obstruction (CCIO). We proposed a new technique based on current SEMS placement with the combined application of ultrathin endoscope and guidewire replacement to solve previous technical difficulties. This study evaluated its feasibility, efficacy, and safety for SEMS placement in CCIO. Methods: We retrospectively analyzed data of 31 CCIO patients, who received the novel SEMS placement technique at Wuhan No.1 Hospital between June 2019 and October 2022. Technical and clinical success rates, adverse events, prognosis, and follow-up were evaluated. Inter-group differences between bridge to surgery (BTS) and palliative treatment (PT) groups and clinical feasibility of this technique were analyzed. Results: Overall technical and clinical success rates were 100% (31/31) and 96.8% (30/31), respectively, without adverse events. There was no significant difference in procedure time and technical/clinical success rates among three attending physicians(p>0.05). Fourteen BTS patients (14/31, 45.2%) underwent SEMS with a post-placement confined operation, which had a 100% success rate (14/14) and no ostomy. Median follow-up time was 67.5 days, and four patients (4/14, 28.6%) had postoperative adverse events of inflammatory anastomotic changes. Seventeen PT patients had a median follow-up time of 30 days, without adverse events. Two patients (2/17, 11.8%) underwent follow-up colonoscopywith no post-placement stent migration/obstruction. Conclusions: The combined application of ultrathin endoscope with guidewire replacement for SEMS placement to treat CCIO could avoid X-ray-induced medical radiation damage and reduce cross-infection risk, making it clinically safe, effective, and promotion suitable.