Device and method of safety automatic detection of air conditioner external unit

The present invention discloses a device and method of safety automatic detection of an air conditioner external unit. The device comprises a support, a detection arm, a positioning mechanism, a detection platform and a safety detector. The detection arm includes a first driving rod, a driving power mechanism, a power supply and earth line probe set, a guidance die capable of positioning and guiding the power supply and earth line probe set and a CASE line probe. The first driving rod is F-shaped, and includes a main rod and two forking rods, the first forking rod is elastically connected with the CASE line probe, and the second forking rod is elastically connected with the guidance die and the power supply and earth line probe set. The guidance die is internally provided with a plurality of through holes, the probes of the power supply and earth line probe set are respectively installed at each through holes, and the positions of the through holes correspond to the positions of wiring terminals to be detecte