Objective To investigate the value of the water pressure method (WPM) for endoscopic submucosal dissection (ESD) of difficult early gastrointestinal cancer. Methods Clinical data of 7 patients with difficult early gastrointestinal cancer who underwent WPM-ESD at Digestive Endoscopy Center of Jiangsu Province Hospital of Chinese Medicine from April 2023 to April 2024 were retrospectively collected. Operation time, complete resection rate and complications were recorded. Results WPM-ESD was successfully completed in all 7 cases. According to the lesion location and factors for difficulty, there were 2 cases of early esophageal cancer (1 case with remarkable external compression, and the other with remarkable hyperkeratosis), 1 case of early gastric cancer (a large lesion located at the greater curvature), 1 case of early descending duodenal cancer (severe submucosal fibrosis due to a history of two sessions of biopsies), 2 cases of early colon cancer (1 case with severe submucosal adipose deposition, and the other with deep submucosal invasion ), and 1 case of early rectal cancer (close to the dentate line). Operation time ranged from 15-85 min. Only 1 case required supplemental rubber-band traction. Complete resection was achieved in all 7 cases. Two patients developed fever postoperatively; no perforation, bleeding or other complications were observed. Conclusion WPM demonstrates feasibility and efficacy for ESD in difficult early gastrointestinal cancer.