The invention discloses a novel secondary voltage drop tester, which includes a main machine and an auxiliary machine, the auxiliary machine includes a second analog signal input circuit, a second analog signal acquisition circuit, a second A / D conversion circuit, and a second main control system , a second working power supply, a second identity recognition control module, a second USB interface, a second button unit, a second display unit, and a second wireless communication module; the host includes a first analog signal input circuit, a first analog signal acquisition circuit, The first A / D conversion circuit, the first main control system, the first working power supply, the first identity recognition control module, the WIFI clock synchronization module I, the first USB interface, the first button unit, the first display unit, and the first wireless communication module. The present invention can not only complete the secondary pressure drop test with high efficiency, high precision and high reliability in a complex test environment, but also improves the safety of the equipment and information of the present invention, avoiding misoperation by non-staff and the loss of related data. Give way.