The invention discloses an active child airbag vest device and a control method thereof, comprising a vest body, a zipper, a lock A, a lock B, a lock C, a lock D, a lock tongue A, a lock tongue B, a lock Buckle tongue C, lock tongue D, webbing A, webbing B, webbing C, webbing D, retracting mechanism, tightening mechanism, deflation control mechanism, inflation port, knob, pressure sensor, vehicle speed sensor, roll angle sensor, side Force sensor, main switch, information storage unit, ECU. Before the child gets on the bus, the car staff will input the child's height and weight information into the information storage unit, and the ECU will control the work of the retracting mechanism according to the child's height and weight information in the information storage unit; the ECU will control the opening and closing of the deflation control mechanism in real time Closing and opening; the ECU receives detection information from pressure sensors, vehicle speed sensors, roll angle sensors, and lateral force sensors as basis for judgment and control. The invention can effectively avoid or reduce children's injury.