The invention discloses a vehicle wire harness detector which comprises a single-chip microcomputer. The single-chip microcomputer is respectively connected with a keyboard input module, a display module, a printing module, a setting module, a learning module, a testing module, a reading module and a PLC control system, wherein the PLC control system is connected with an external wiring harness, and the external wiring harness is placed on a wiring harness clamp. The wiring harness clamp has a U-shaped seat where a U-shaped groove capable of receiving the wiring harness is formed. One side of the U-shaped seat is in hub connection with a cross bar, the other end of the U-shaped seat is provided with a groove matching with the cross bar, and a solenoid valve is installed on one side of the U-shaped seat. The wiring harness clamp has a U-shaped seat where a U-shaped groove capable of receiving the wiring harness is formed. One side of the U-shaped seat is in hub connection with a cross bar, and the other end of the U-shaped seat is provided with a groove matching with the cross bar. A wire harness to be detected is locked in the U-shaped groove. The operation is very convenient, the detection efficiency is improved, and the structure is simple.