Error correcting method for step out of stepping motor

The invention relates to an error correcting method for step out of a stepping motor, which is characterized by comprising the following steps: at idle speed, measuring the total air flow entering the motor; subtracting the air leakage of a throttle body of the corresponding engine type from the total air flow entering the motor measured in the step A to calculate the actual air flow flowing through the stepping motor; according to the actual air flow flowing through the stepping motor calculated in the step B, inquiring a flow characteristic curve of the stepping motor to obtain the corrected value of the stepping motor; and when a step out correction enabling condition is met, substituting the corrected step number for the step number of out-of-step for carrying out correction.