A drive control device which estimates an engine torque during traveling in a fixed gear ratio mode is disclosed. The drive control device includes the engagement mechanism including the revolution component revolved by the torque of the engine and the fixed component that engages with the revolution component, the torque applying unit which applies torque to the revolution component and the first transmitting control unit which engages the engagement mechanism to make the engagement mechanism receive the reaction force of the torque. The torque estimating control unit executes control of torque applied to the revolution component by the torque applying unit during executing the control by the first transmitting control unit to detect the phase change between the revolution component and the fixed component and estimates the torque of the engine based on the phase change and torque applied by the torque applying unit.