In order to enhance the service performance of epoxy resin dry-type distribution transformer, taking a 10 kV/0.4 kV epoxy resin dry-type distribution transformer as the research object, a structure optimization design method for dry-type distribution transformer based on the multi-objective starfish optimization algorithm (MOSFOA) was proposed. Firstly, a transformer model coupling electromagnetic-thermal-mechanical fields was established for performance simulation. The cross-sectional areas of the high/low voltage winding conductors, the width of the air ducts, and the radius of the core were determined as the core design variables. Subsequently, high-precision surrogate models linking the design variables to the hotspot temperature rise, loss and short-circuit electromagnetic force per unit volume of the high/low voltage windings were constructed using central composite design and response surface methodology. Finally, collaborative optimization based on the MOSFOA was performed to obtain the optimal combination of structural parameters.The resultsindicate that, while maintaining the insulation safe, compared with the initial plan, the hotspot temperature rise, loss, and short-circuit electromagnetic force per unit volume of the high/low voltage windings were reduced by 22.91%, 33.37%, 9.39%, 42.82%, and 45.52% respectively after optimization. This verified the effectiveness of the proposed optimization method.The research results provide a new method for the optimization design of dry-type transformers, and have significant reference value for improving the design efficiency and operational reliability of dry-type transformers.