The invention relates to the field of mechanical control, in particular to a supporting leg control device. The device judges the supporting leg state through two variables including the torque and the stroke, the torque serves as the main judgment basis, and it is ensured that the leg withdrawing zero return position is within the reasonable range. The sliding column zero return position each time is determined at random, the torque change in the reasonable range can be well recognized in the zero return process, long-term stable running of the control device is ensured, the supporting leg fault period is reduced, and reliability of the control device is improved.