Surface discharge is one of the most severe discharge faults in transformer oil-paper insulation structures. In order to accurately obtain the variation characteristics of characteristic parameters during the development process of surface discharge under AC voltage, this study constructed a simulation experimental platform for the development process of surface discharge and established a measurement system that can meet the synchronous online monitoring requirements of three physical quantities: electrical, magnetic, and acoustic. Based on this, the typical characteristics of multiple physical parameters during the development process of surface discharge are extracted. Compared with conventional single-parameter monitoring methods, the multi-parameter synchronous detection method provides a more reliable and accurate reference for the diagnosis and timely warning of surface faults in transformers.