The invention relates to an automobile instrument detection system, and specifically relates to an automobile instrument detection system based on STM32. The detection system includes a microcontroller, a switching signal unit connected to the microcontroller, a bus unit, a PLC unit, a serial communication unit, a unit power supply unit, a storage unit, a relay control unit, a voltage acquisitionunit, a resistance network unit and a waveform generation / acquisition unit, wherein the switching signal unit, the bus unit, the PLC unit, the serial communication unit, the unit power supply unit, the storage unit, the relay control unit, the voltage acquisition unit, the resistance network unit and the waveform generation / acquisition unit are connected with the microcontroller. The microcontroller is connected to an upper computer through a serial port, and the switch signal unit includes a 74HC595, optocouplers TPL700 and a short circuit protection circuit, wherein the 74HC595 converts a serial control signal of the controller into a parallel signal, the 74HC595 is connected with multiple optocouplers TPL700 and the short circuit protection circuit is connected with the optocouplers TPL700. The automobile instrument detection system based on STM32 in the technical scheme of the invention has the characteristics of multiple signal types, high precision, strong anti-interference capability, convenience in programming and the like.