This paper presents a compensation topology identification method based on DC input voltage and current. The method only uses the DC input voltage and current of the inverter to identify the compensation topology of the wireless charging system. Firstly, two wireless power transfer (WPT) system models were established, one with an S-S compensation topology and the other with an S-LCC compensation topology. Then, the relationship between DC input voltage and input current of inverter is deduced according to the model. In view of the charging characteristics of constant voltage wireless charging system, the soft start process is divided into two stages, and the specific compensation topology is identified by comparing the relationship between the DC input voltage and the input current of the inverter in the two stages. Finally, the prototype of WPT system is built, and the effectiveness of the method is verified by simulation. The results show that this method can identify the compensation topology accurately using only the primary DC parameters, which is helpful to the research and analysis of wireless charging system interoperability.