The invention provides a wheelchair auxiliary device structure for stair lift.It includes a wheelchair.The wheelchair has a frame.Chair,Front wheel set and rear wheel drive set,The rear wheel drive group is provided with a tooth plate.An auxiliary device,The auxiliary device is provided with a connecting pipe body.The connecting pipe body is provided with a connecting part.The connecting part is provided with a roller.The connecting pipe body group is provided with a transmission gear group.Each side of the frame is provided with an auxiliary device.A chain is arranged between the transmission gear set and the gear plate.And a track group,The track is set on the wall of the stairwell.The track group is provided with a plurality of sprockets.The chain wheel is engaged with the driving gear set.The track group is clamped with a plurality of rollers.Driving the transmission gear group through the rear wheel drive group,The wheelchair can be lifted and lowered in the stairwell.本創作提供了一種用於樓梯升降之輪椅輔具裝置結構,其包括一輪椅,該輪椅有車架、坐椅、前輪組及後輪驅動組,該後輪驅動組設有一齒盤,一輔具裝置,該輔具裝置設有組接管體,該組接管體設有組接部,該組接部穿設有滾輪,該組接管體組設有一傳動齒輪組,該車架側邊各組設一該輔具裝置,該傳動齒輪組與該齒盤之間設有一鍊條,以及一軌道組,該軌道組設於樓梯間之壁面,該軌道組設有複數鏈輪,複數該鍊輪與該傳動齒輪組咬合,該軌道組與複數該滾輪卡合,透過該後輪驅動組帶動該傳動齒輪組,即可達到於該樓梯間升降該輪椅之功效。