Objective To analyze the relationship of closed staple height with tissue damage and compression pressure, so as to provide theoretical references and guidance for the surgeon to choose the appropriate staple cartridge and height, as well as improve the safety of operation. Methods The finite element model of stapled colorectal end-to-end anastomosis was established based on analysis of staple-tissue interaction. Large intestine tissues with different wall thicknesses (1.0-1.5 mm) were compressed by closed staples with 4 different height to compare changes in stress distributions and average radial pressure. Results When the tissues were compressed by closed staple with height of 1.0, 1.1, 1.2 and 1.5 mm, respectively, the average radial stress of compressed tissues with wall thicknesses of 1.2, 1.3, 1.4, and 1.5 mm were 56.0, 58.6, 59.7 and 57.3 kPa, respectively, which was close to the optimal compression pressure. Stress concentrations were found in contact area of the staple and tissues，with the maximum stress being 2 783, 1 750, 1940 and 2 030 kPa, respectively. Conclusions Tissue damage cannot be completely avoided in anastomotic surgery, and stress concentration is generally located near contact region of the staple and tissues. The optimal closed staple height ranges in 50%-60% of the uncompressed tissue height.