Charge state parameter correction method and device and working machine

The invention provides a charge state parameter correction method and device and a working machine. The charge state parameter correction method comprises the following steps: receiving charge state incredible sign information; in response to the charge state incredible sign information, acquiring the maximum charging power of the vehicle-mounted charger output by the vehicle-mounted charger and the average required power of the motor within the target time period threshold; based on the maximum charging power of the vehicle-mounted charger, the average required power of the motor and the capacity parameter of the battery system, determining a correction range threshold value of the charge state parameter; and based on the correction range threshold value of the charge state parameter, controlling the target charging power of the vehicle-mounted charger, enabling the real-time charge state parameter to be within the correction range threshold value, and correcting the target charge state parameter of the batt