This study shows the 4 - Bar linkage design process and static/dynamic stability analysis of a foldable electric wheelchair that can be loaded into a vehicle for long-distance trips. Conventional foldable electric wheelchairs have been developed for indoor use because the safety of the disabled is not secure enough for outdoor use. However, the disabled have generally used foldable electric wheelchairs for outdoor use, potentially putting themselves in a dangerous situation. The body of a foldable electric wheelchair consists of a double 4 - Bar linkage system that shares one link. The architecture of the wheelchair’s four-bar linkage frame was synthesized using four finitely separated design positions. This simple method can design a planar four-bar mechanism through the use of four finitely separated poses (orientation and position). The power driving module includes a battery and controller, and can be separated to load into a car easily. An analysis of the tip-over measurement was performed using ADAMS and LifeMOD during a maneuver on the ground. by force-moment stability metric. Several elements, including the center of gravity position, rotational radius, and acceleration, were evaluated how to affect stability metric.