The invention discloses a method for analyzing factors influencing cooling efficacy of split cooling transformers. The method comprises the following steps of: establishing a model of a split cooling transformer by utilizing finite element software and carrying out mesh generation; setting a boundary condition; setting ideal sample analysis temperature field distribution; and changing an external environment condition and an internal structure, and carrying out analog computation to obtain influences, on the cooling efficacy, of the external environment condition and the external structure. By utilizing the method, theoretical basis can be provided for the cooling efficacy of split cooling transformers, and temperatures of specific points in temperature files of the split cooling transformers under extreme environment can be grasped, so as to measure whether the transformers are operated safely and then carry out necessary maintenance on the transformers. According to the method, theoretical guidance can be provided for the internal structure improvement and outdoor arrangement manners of the split cooling transformers, and the superiority, for improving the cooling efficacy, of split cooling systems can be verified.