PURPOSE: To control a line pressure of setting a proper pulley groove width by finding out an estimation value of acceleration from engine torque and actual speed ratio and also a change rate of an actual car speed, and controlling the line pressure by a preset torque map data in the case that a difference between the found estimation value and change rate is a predetermined value or more.

CONSTITUTION: In an engine control unit 2, engine torque is calculated to find an estimation value of acceleration of a vehicle from this engine torque and actual speed ratio and a change rate of an actual car speed through information of a car speed sensor IC. In the case that an absolute value of a difference between the estimation value and the change rate is a predetermined value or less, a line pressure for setting a groove width by a CVT control unit 1 is found based on engine torque information. In the case of the predetermined value or more, information of the engine control unit 2 is judged abnormal, to find the engine torque based on a throttle opening and an engine speed by a preset engine torque map data and a line pressure for setting the groove width by the CVT control unit 1 based on this engine torque. By the above, even at the time of trouble in an information transmitting route, the line pressure can be controlled by a condition similar to the normal.