A towing assist device includes an imaging device configured to capture a rear area from a towed vehicle when a towing vehicle moves backward, the towed vehicle being connected to the towing vehicle via a connector; a monitor device including a display screen configured to display a captured image which is captured by the imaging device, a touch screen function for detecting a touch position to the display screen; and a controller that is connected to the imaging device and the monitor device and is configured to control a display of the monitor device when the towing vehicle moves backward. The controller includes a display setting processing portion, a model display processing portion, a touch operation detection portion, and a movement direction model display processing portion.