A device for detecting a load state of a DC driving power supply, comprising: a DC driving power supply; a load; a first resistor; a second resistor; and a main control unit; the load, the first resistor and the second resistor are connected in series and connected to the driving power supply; and one end of the second resistor is grounded, the main control unit is provided with an input/output interface, a switchable pull-down resistor module, a level detecting module and a control module; the input/output interface is connected to the common end of the first resistor and the second resistor; the level detecting module is configured to detect the level of the input/output interface, and the high potential end of the pull-down resistor module is connected to the input/output interface; the low potential end of the pull-down resistor module is grounded, and the control module is connected to the control end of the pull-down resistor module; a parasitic capacitance is generated on the circuit between the input/output interface and the common end of the first resistor and the second resistor, wherein the driving power supply is configured to supply power to the load; the control module is configured to turn off the pull-down resistor module in the main control unit; the main control unit is configured to start timing, and the level detecting module is configured to start detecting the voltage level of the input/output interface; wherein if the level detecting module detects that the voltage level on the input/output interface reaches the expected value in the process of timing, it is determined that the driving power supply is in a normal load state at this time; and if the level detecting module does not detect that the voltage level on the input/output interface reaches the expected value after the timing is completed, it is determined that the driving power supply is in a no-load state at this time; wherein the control module is further configured to turn on the pull-down resistor module in the main control unit when it is determined that the driving power supply is in a normal load state. a DC driving power supply; a load; a first resistor; a second resistor; and a main control unit; the load, the first resistor and the second resistor are connected in series and connected to the driving power supply; and one end of the second resistor is grounded, the main control unit is provided with an input/output interface, a switchable pull-down resistor module, a level detecting module and a control module; the input/output interface is connected to the common end of the first resistor and the second resistor; the level detecting module is configured to detect the level of the input/output interface, and the high potential end of the pull-down resistor module is connected to the input/output interface; the low potential end of the pull-down resistor module is grounded, and the control module is connected to the control end of the pull-down resistor module; a parasitic capacitance is generated on the circuit between the input/output interface and the common end of the first resistor and the second resistor, wherein the driving power supply is configured to supply power to the load; the control module is configured to turn off the pull-down resistor module in the main control unit; the main control unit is configured to start timing, and the level detecting module is configured to start detecting the voltage level of the input/output interface; wherein if the level detecting module detects that the voltage level on the input/output interface reaches the expected value in the process of timing, it is determined that the driving power supply is in a normal load state at this time; and if the level detecting module does not detect that the voltage level on the input/output interface reaches the expected value after the timing is completed, it is determined that the driving power supply is in a no-load state at this time; the driving power supply is configured to supply power to the load; the control module is configured to turn off the pull-down resistor module in the main control unit; the main control unit is configured to start timing, and the level detecting module is configured to start detecting the voltage level of the input/output interface; wherein if the level detecting module detects that the voltage level on the input/output interface reaches the expected value in the process of timing, it is determined that the driving power supply is in a normal load state at this time; and if the level detecting module does not detect that the voltage level on the input/output interface reaches the expected value after the timing is completed, it is determined that the driving power supply is in a no-load state at this time; wherein the control module is further configured to turn on the pull-down resistor module in the main control unit when it is determined that the driving power supply is in a normal load state.