A control device of a powertrain with a centrifugal pendulum damper is provided, aiming at providing a control device which can prevent deterioration of the transmission property caused by changes to tightening level of a disconnection mechanism. The control device comprises a power transmission shaft (3b) which transmits power between a drive source (1) and an automatic transmission (3), and a centrifugal pendulum damper (13) which is coupled to the power transmission shaft (3b) and a connection/disconnection mechanism (14). The automatic transmission (3) has a transmission mechanism (3a) of a hydraulic pressure control type, which includes a transmission control module (120) which performs a control to supply transmission hydraulic pressure to the transmission mechanism (3a). The transmission control module (120) includes a transmission characteristic changing module (125) which changes a control characteristic of transmission hydraulic pressure according to an engagement degree of the connection/disconnection mechanism (14).