The invention provides a smart bed chair. A bed body and a wheelchair are fitted by a connecting device; the connecting device comprises an upper locking mechanism, a lower locking mechanism, a bed guiding wheel and a bed guiding rail, the bed chair comprises a radar system capable of detecting an obstacle, controllers, an alarm system and an electromagnetic active braking system, the radar systemis four ranging radars mounted around the front, rear, left and right of the wheelchair to detect the surrounding obstacles, the controllers are installed behind a wheelchair back plate and an armrest of the wheelchair, an alarm system includes an alarm device which is a horn mounted on a headrest of the wheelchair and a buzzer installed at the armrest, and the electromagnetic active braking system is installed at two driving wheels; the bed chair is provided with a Bluetooth mechanism, and the Bluetooth mechanism is connected to a smart device app. The bed chair uses the radar system, the controllers, the alarm system and the electromagnetic active braking system, can actively detect the obstacles, achieves the purposes of active alarm, deceleration and braking, and reduces the occurrence of accidents.