The carbon emissions estimation during the construction phase of port engineering is a crucial method for quantifying the carbon emissions throughout the port’s entire life-cycle and advancing energy-saving and carbon reduction efforts.Addressing challenges such as the lack of source references for carbon emissions estimation coefficients and unclear valuation methods during the construction phase,we propose applying the “engineering carbon emission quota method” to the construction phase of port engineering.By integrating the project’s bill of quantities and current engineering quota standards,we calculate the carbon emissions of individual sub-projects and the overall project emissions on the basis of the life cycle assessment(LCA) method.Through providing valuation methods for carbon emission quotas in underwater dredging,foundation bed rock throwing,foundation work,and dredging projects,and applying the “engineering carbon emission quota method” to a real-world port terminal construction project,we estimate the total project carbon emissions at 33,200 tCO2,with material (equipment) production and transportation accounting for approximately 79% and energy consumption for about 21%,offering valuable insights for carbon emission analysis during the construction phase of port projects