The utility model relates to a displacement auxiliary device, which comprises a base body, two chair seats, two positioning parts and a leaning knee, wherein the base body comprises a support frame and a foot step seat connected with the support frame.The seat is movably connected with the support frame to move or displace to a riding position, which is used to define a riding space between the support frame, the foot rest and the seat.The positioning parts can be detachably connected with the support frame and the seat, so that the seat can be positioned in the riding position, so as to improve the safety of product use.The knee rest is movably connected with the support frame and adjacent to the aforementioned riding space, so as to properly adjust according to the body shape of the passenger and improve the riding comfort.一種移位輔助器,包含:一座體、二椅座、二定位件及一靠膝,其中,該座體包括一支撐架及連接該支撐架之一腳踏座。前述椅座皆活動地連接該支撐架,以移開或位移至一乘坐位置,該乘坐位置用以在該支撐架、該腳踏座及前述椅座之間界定一乘坐空間。前述定位件皆可拆地連接該支撐架及前述椅座,使前述椅座確實定位於該乘坐位置,以增進產品使用的安全性。該靠膝活動地連接該支撐架且相鄰前述乘坐空間,以便於依照乘坐者的體型適當調整,增進乘坐的舒適性。