The invention discloses a vehicle automatic-drive switching device and method based on distracted driving behavior distinguishing. The device comprises a detection unit and a control unit. The input end of the detection unit is connected with a speed sensor, a three-axis acceleration sensor, a steering wheel turning angle sensor, a steering wheel gripping force sensor, a touch sensor, a ranging sensor, a heart rate sensor, a vehicle data recorder and a GPS. The control unit receives significant variable data and time data of a timer, establishes the relation between vehicle automatic-drive probability dependent variables and distracted driving behavior index independent variables on the basis of a logistic regression model, and works out the vehicle automatic-drive probability. Whether given conditions are met or not is judged through a judging condition I and a judging condition II of a condition judging program, if the judging condition I is met, an automatic early-warning control switch is triggered, and if the judging condition II is met, a vehicle automatic-drive control switch is triggered.