Abstract: In the trenching and burying construction of submarine pipeline, except the pipeline's near-shore sections which adopt the pre-trenching method, other marine sections generally use post-trenching and burying with submarine trenchers. In post-trenching construction, the submarine pipeline trencher shoots the submarine mud surface with a high-pressure jet flow to form the desired ditch shape, and the mud and sand that are broken up by the jet pump in the shooting process should be discharged from the work area in a timely manner. Based on the analysis of jet pump design principles, basic equation of jet pump and jet pump performance curve, the authors the determination methods and procedures of jet pump parameters of submarine pipeline trenchers (the largest earthwork flow, flow ratio, head ratio, area ratio, jet volume flow, etc.) are proposed, providing a basis to the determination of related parameters of submarine pipeline trenchers and selection of main equipments.