PURPOSE: To provide a steering control device capable of making a turn safely by automatically conducting a pivot turn despite that a combine is making any kind of turning when a lever position detecting device is out of order.

CONSTITUTION: When the disconnection in a mode detecting means 96 of a turn mode exchanging lever 95 occurs in the middle of making a right mild turn, a lever trouble detecting means 99 detects 0V or the maximum output voltage of 5V from the mode position detecting means 96, and the controlling part outputs the controlling signal for making a pivot turn. In the pivot turn, a hydraulic pressure is applied to the port of a side clutch brake and right hand side clutch becomes 'off'. Further, a right brake reducing valve together with a right clutch exchanging valve are exchanged to 'in'. By a pivot turn commanding signal, the output pressure of the right brake reducing valve increases to a prescribed value to actuate a right brake and a braking action is applied to the rotation of a rotating case. In this way, when the disconnection of the mode exchanging lever occurs during the turning, it is possible to promptly make the steering the pivot turn to hold the turning and to safely perform the turning motion. Therefore, the operator can safely perform the steering operation without getting bewildered.