Feedback bus signal detection circuit and device of OBD interface

The utility model discloses a feedback bus signal detection circuit and device of an OBD interface. The feedback bus signal detection circuit of the OBD interface comprises a main control module, an input power supply processing module, a K line detection module and a CAN line detection module. The K line detection module comprises a first K line detection unit and a second K line detection unit; the CAN line detection module comprises a first CAN line detection unit and a second CAN line detection unit; the input power supply processing module is electrically connected with an input power supply and the main control module respectively; the first K line detection unit is electrically connected with a K bus and the main control module respectively, and the second K line detection unit is electrically connected with the K bus and the main control module respectively; the first CAN line detection unit is electrically connected with a CAN bus and the main control module respectively, and the second CAN line dete