A display system and a display system detection method are provided. The display system includes: a main control unit configured to output a first detection signal to a switch unit, and calculate the connection resistance according to a connection voltage and a detection current; a switch unit configured to control the cable to generate a detection current and a detection voltage according to the first detection signal; a constant current control unit configured to stabilize the detection current and the detection voltage; and a voltage detection unit configured to generate a connection voltage according to the detection voltage, and send the connection voltage and the detection current to the main control unit.