The invention relates to a determination method of transformer liquid bag press fitting, and belongs to the technical field of manufacturing of transformer and electric reactor process. The technical scheme includes that the method includes the steps: summarizing and inducing relations between liquid bag hose pressure and liquid bag hose height by the aid of experimental verification data; comparing calculated values of the liquid bag hose height in the relations with actual values to obtain end conditions controlling liquid bag press fitting. The determination method has the advantages that the end conditions of liquid bag press fitting process can be simply and visually controlled, so that liquid bag press fitting products meet press fitting effect, product quality is ensured, and the determination method is simple and convenient to operate, good in practicability and easy to popularize and apply.