Provided is a control device for controlling a belt-type stepless speed change device including: a hydraulic actuator for changing a groove width of a primary pulley; a hydraulic actuator for changing a groove width of a secondary pulley; and a belt-sandwiching force control solenoid which controls a hydraulic pressure supplied to the hydraulic actuator of the secondary pulley. The control deviceincludes: means for calculating a speed change ratio between the primary pulley and the secondary pulley and judging whether belt sliding is present according to the calculated speed change ratio; and means for judging whether the belt-sandwiching force control solenoid is normally operating. The condition for judging the normal operation is based on an input torque when a belt sliding has actually occurred, i.e., when it is judged that a failure has occurred. By using such a condition setting, it is possible to reduce the normal operation judgment threshold value (input torque value alpha) used for the normal operation judgment and suppress incorrect judgment of the normal operation.