The　fundamental　harmonic　approximation　method　is　the　main　research　method　of　wireless　power　transfer　(WPT)　technology.　This　method　equates　the　rectifier　load　fundamental　impedance　to　a　pure　resistance,　which　provides　a　basis　for　modeling　and　analysis　of　the　WPT　system.　However,　this　method　ignores　the　effect　of　rectifier　load　harmonic　impedance,　which　leads　to　a　large　error　between　the　actual　response　and　the　theoretical　analysis,　affects　the　model　accuracy　of　the　system　and　limits　the　further　optimization　design　of　WPT　system.　In　this　paper,　the　WPT　system　based　on　parallel-series/series　(PS/S)　compensation　network　is　taken　as　the　research　object,　the　reason　for　the　error　generated　by　the　fundamental　harmonic　approximation　method　is　analyzed　and　an　accurate　calculation　method　based　on　the　iterative　method　for　the　rectifier　load　equivalent　impedance　is　proposed.　On　this　basis,　an　accurate　circuit　response　model　of　the　WPT　system　is　established.　Finally,　the　correctness　of　the　system　response　model　is　verified　through　simulation.　©　2022　IEEE.