When contactless power transmission (CPT) systems are operating normally, load variation will cause the system operating frequency to drift and the resonance frequency scope to deviate from the desired level. These fluctuations in turn cause the system to vary substantially and affect its normal operation. Considering the slip road track of the primary circuit and the phase angle change between the front of the subnetwork rectifier circuit current and the voltage, we employ different circuit models to analyze the nature and size of the load for the two types of antiperceptual situations. An algorithm is derived to calculate the junior circuit parameters with the load on the rails. Simulation analysis for the load identification under two different load conditions is conducted, and the expected results achieved.