An automatic stabilizing device. A base plate includes a through hole. An imbalance detecting mechanism is disposed on the base plate and includes a detecting member and an engaging member connected thereto. The detecting member is movably disposed inside the through hole. A sliding support plate is disposed on the base plate and detachably connected to the imbalance detecting mechanism. The sliding support plate includes an engaging hole in which the engaging member is detachably engaged. A first resilient member is connected between the base plate and the sliding support plate, providing a first predetermined resilience to the sliding support plate. When the base plate swings to extend the detecting member from the through hole, the engaging member moves and disengages from the engaging hole, and the sliding support plate slides to protrude from the base plate by the first predetermined resilience.