The invention relates to the technical field of toys, and discloses an automatic toppling prevention device for a baby walker. The device comprises a shell, a button is fixedly connected to the outer part of the shell, an angle detection assembly is movably connected to the outer part of the shell, a motor is fixedly connected to the inner part of the shell, and a reciprocating lead screw is movably connected to the inner part of the shell. Under the interaction of the angle detection assembly, the motor, the reciprocating lead screw, a reciprocating groove, a reciprocating block, a connecting rod, a sliding rail, a retraction detection assembly, an extension detection assembly, a sliding block, a supporting shaft, an electromagnetic pump and a gas storage assembly, when a child topples over while riding the baby walker, the inclination condition of the baby walker can be detected at the first time under the action of the angle detection assembly and the supporting shaft, the supporting shaft can be rapidly stretched out to prevent the baby walker from continuing to incline, and therefore it is guaranteed that a child can exercise trustingly, and the situation that riding of the child is affected by the baby walker is avoided.