The galvanic-coupled intrabody communication (GCIBC) uses the human body as the channel for data transmission. The signal flow through different paths within different measurement schemes, resulting in distinct deviations in the experimental results. This method completely uses human body channel to transmit low-power signals, and has good anti-interference performance. However, for a long time, the channel research of GCIBC has not determined a set of recognized and accurate measurement methods and standards. However, few researcher analyze the differences and principles between different measurement methods. This paper aims at three commonly used measurement methods. Abstract the equivalent schematic diagrams of three measurement schemes: direct measurement, using high-precision differential probe and using balun. The signal return paths generated by three measurement methods are analyzed, the impedance matching and energy transmission efficiency are compared. According to the analysis, the empirical expressions in different cases are listed. The mechanism between the channel measurement results generated by the set experimental configuration and the comparison experiment is clarified. The comparison experiment with complete floating measurement is carried out as a reference to verify the proposed opinion. The measurement error caused by different experimental configurations is verified. This study can provide a reference opinions for the experimental error analysis of GCIBC research in the future, and provide suggestions for the selection of experimental configuration.