An acceleration detection device includes an acceleration sensor that has a first detection axis and a second detection axis such that a yaw mounting angle between a vehicle reference axis and a virtual line is ±15 degrees or less, an acquisition section acquiring an acceleration in a direction of the first detection axis and an acceleration in a direction of the second detection axis, and a mounting angle calculation section calculating the yaw mounting angle from an angle calculation formula and the acceleration in the direction of the first detection axis and the acceleration in the direction of the second detection axis.