Collision avoidance assistance device

The present invention provides a collision avoidance assistance device capable of improving functionality and usability by suppressing excessive operation or sudden operation of braking in collision avoidance assistance for an object traveling on a lane orthogonal to a host vehicle (a road crossing the host vehicle). A predicted collision point arrival time, which is a predicted time until the vehicle arrives at the predicted collision point when the vehicle is decelerated at a predetermined deceleration or braking force, is calculated. A braking operation determination threshold value is changed (increased or decreased) on the basis of a predicted passage time, which is a predicted time required for an object to pass through an intersection region (predicted intersection region) between a predicted travel road (target predicted travel road) of the object and a predicted travel road (predicted travel road of the own vehicle) of the own vehicle, and a predicted collision point arrival time. 本发明提供一种在针对在与自身车辆正交的