A drive control device includes: an estimated longitudinal acceleration acquisition part acquiring an estimated longitudinal acceleration of a vehicle based on an estimated driving force of the vehicle and a wheel speed of main drive wheels of the vehicle; an estimated lateral acceleration acquisition part acquiring an estimated lateral acceleration of the vehicle; an estimated tire load calculation part calculating an estimated tire load of the main drive wheels based on the estimated longitudinal acceleration and the estimated lateral acceleration; and a drive mode selection part selecting one of a two-wheel drive mode driven only by the main drive wheels and a four-wheel drive mode driven by both the main drive wheels and auxiliary drive wheels. When the estimated tire load calculated by the estimated tire load calculation part is lower than a two-wheel drive threshold value, the drive mode selection part selects the two-wheel drive mode.