A control device for a power transmission mechanism, includes: a continuously variable transmission including a primary pulley, a secondary pulley, an oil pump; and a hydraulic control device to control a primary thrust for moving a primary movable sheave of the primary pulley and a secondary thrust for moving a secondary movable sheave of the secondary pulley, so that in a case where a secondary target pressure for generating the secondary thrust is smaller than an oil pump discharge capacity when a maximum gear ratio is requested, a primary target pressure for generating the primary thrust is made smaller than that in a case where the secondary target pressure is larger than an oil pump discharge capacity.