Abstract: Based on the British standard BS7910, the fracture assessment of level 2A was performed using the Crackwise4.0 software for the embedded flaw, which were formed when the submarine pipeline was installed, in the context of defects acceptance. The influence of fracture toughness, primary stress and mechanical properties on the critical crack size was analyzed using sensitive functions and factors, and the values of sensitivity were obtained respectively. Depended on the benchmark set in this paper, for a certain crack length the crack height was most affected by the yield strength at room temperature. As the critical crack length increased, the effect of primary stress on the critical crack height increased and the influence of fracture toughness as well as theyield strength at room temperature decreased relatively. However, the critical crack height was not sensitive to the tensile strength at all.