Abstract: Heating cycle voltage test is an important test item to evaluate its long-term aging characteristics. Provide a basis for the main loop temperature control through the analog loop. Limited to the test site, the analog circuit is generally placed inside the test circuit, thereby generating an induced current. In order to investigate the influence of induced current on test accuracy, this paper uses multiple sets of test control variables to analyze the induced electric current generated by cables under different loop conditions. The characteristics and laws of induced currents between the two loops are obtained by comparison. The research shows that under the premise that the two loops generate equal magnitude current, the current direction of the two loops is the same, the output power of the main loop is reduced, and the output power of the analog loop is increased; the current direction of the two loops is opposite, the output power of the main loop is increased, and the output power of the analog loop is reduced.