A wheelchair.Including: a wheelchair body,Having a first junction；A power assist device,It has a bracket.One round group,One motor unit,One clutch and one control interface,The wheelset is arranged at the bottom of the bracket.The wheel group has a second joint.The motor unit is arranged on one side of the wheel set.To provide rotational power,The clutch system is arranged on one side of the wheel set.It can switch back and forth from one electric position to one manual position.When the clutch is in the electric position,It is used to transfer the power of the motor unit to the wheel set.When the clutch is in the manual position,The power of the motor unit is blocked without being transmitted to the wheel set.The control interface is set at the top of the bracket.It is used as the user to control the start-up of the motor unit.Shut down, increase or decrease of rotation speed and control the steering of the wheel set；The second joint part of the power assist device is connected with the first joint part of the wheelchair body in a detachable manner.一種輪椅，包含有：一輪椅主體，具有一第一結合部；一動力輔助裝置，具有一支架、一輪組、一馬達單元、一離合器及一控制介面，該輪組係設置於該支架底部，該輪組上具有一第二結合部，該馬達單元係設置於該輪組一側，用以提供旋轉動力，該離合器係設置於該輪組一側，可於一電動位置至一手動位置間進行往復切換，當該離合器位於電動位置時，係用以將該馬達單元之動力傳遞至該輪組上，當該離合器位於手動位置時，係將該馬達單元之動力加以阻絕而不傳遞至該輪組上，該控制介面係設置於該支架頂部，用以作為使用者控制該馬達單元之啟動、關閉與轉速增減及控制該輪組之轉向者；該動力輔助裝置之第二結合部係與該輪椅主體之第一結合部以可拆離之方式結合。
