Abstract: The suspended section of a submarine pipeline is vulnerable to resonant vibration and local deflection under the combined effect of wave and current. Length of span is one of the key influential factors. As to the ultimate strength of temporary pipeline span, this paper provides the approach and process to calculate the allowable maximum span in aspects of deflection strength, yield strength and resonance strength, and adopts VBA language to develop the calculating and analysis software for the allowable maximum span of suspended submarine pipeline section. Based on case study, the allowable maximum spans of submarine pipeline at different stages of service life are acquired. Relevant approach and software can provide effective support for field engineers to solve problems in assessment on temporary span, so as to accelerate the process of the whole project.