A hydraulic pressure control device is provide for a belt type continuously variable transmission that appropriately controls hydraulic pressure supplied to each pulley. The hydraulic pressure control device has a positive input torque calculation section that calculates a positive input torque that is inputted to a primary pulley from an engine; a reverse input torque calculation section that calculates a reverse input torque based on the calculated speed ratio and the positive input torque; and a hydraulic pressure regulation section that calculates a hydraulic pressure of hydraulic fluid supplied to each pulley depending on the sum of the positive input torque and reverse input torque and controls hydraulic pressure to each the pulley to the calculated hydraulic pressure.