Abstract: To address the lack of low-carbon representation in current business park planning, a bi-level planning methodology for business parks' integrated energy systems considering low-carbon dual constraints is proposed. The carbon emission and carbon reduction boundaries of the business park are delineated, an accurate carbon emission accounting model for the energy system of the park is constructed, and a low-carbon operation index considering the trend of overall carbon emissions and carbon emission reduction as well as the carbon emissions per unit of electricity is proposed, which constitutes the low-carbon dual constraints of the planning model together with the carbon transaction cost. With the goal of optimizing the annual comprehensive cost of the park and considering low-carbon operating constraints, different time scales are established for the two-tier planning model. The upper-level model determines the system configuration for the entire year, while the lower-level model optimizes the operation of equipment on a daily time scale. The RIME algorithm and CPLEX solver are jointly used for simulation and solution. Through simulation, the feasibility of imposing low-carbon assessment constraints to ensure the park operates within the low-carbon range is validated. The impact of the size of low-carbon operating constraints and the setting of time scales on the system planning results is also explored.