The device is mainly divided into four parts, using the encoder control program to ensure that the four systems work independently and coordinate with each other to complete a series of functions. The upper part of the wheelchair adopts an integrated structure, in which the back and the armrest can be tilted through the winch mechanism, so as to realize the adjustment of the sitting posture of the elderly. The layered transmission mechanism in the middle part of the wheelchair drives the lead screw to rotate through the motor and then drives the slider to rotate, which can realize the overall lateral movement and longitudinal movement of the upper part of the wheelchair together with the elderly, so that the elderly can get on and off the bed and adjust the overall center of gravity of the wheelchair. The lower part of the wheelchair drives the worm gear to rotate through the motor, and then adjusts the angle of the connecting rod at the bottom of the wheelchair. The six-wheel mechanism of the connecting rod at the bottom of the wheelchair is responsible for adjusting the overall height of the wheelchair, and can cross small steps including sidewalks and simple roadblocks. The upper part and the backrest of the wheelchair adopt an integrated structure. The motor at one end of the seat plate drives the gear to rotate, and the rope is connected with the backrest to form an integrated hoisting mechanism. Realize the inclination of the back and the armrest and the wheelchair back and the side armrest adopt a hoist-type integrated structure, and the motor drives the gear set to rotate to drive the rope connected to the wheelchair back, thereby realizing the angle adjustment of the wheelchair back and the armrest. The elderly and users can adjust the angle of the wheelchair back by controlling the switch located next to the armrest, so as to realize the free adjustment of the user's sitting posture and the state of the armrest. The middle part of the wheelchair adopts a lead screw and a slider as a transmission structure, a light rod bracket as a support structure, and a layered lead screw transmission structure. The layered lead screw transmission mechanism adopts a double-layer splicing structure, which can ensure that the operation of the lead screw is not affected by each other on the basis of independent work. The upper layer has a horizontal extension function, and the lower layer has a longitudinal extension function. The motor drives the screw to rotate to drive the sliding block to reciprocate, which not only realizes the overall horizontal and vertical extension and retraction functions of the upper part of the wheelchair, but also operates more stably than the traditional slide rail structure, and can freely control the extension stroke. So as to realize the function of sending the upper part of the wheelchair to the bed so that the elderly can get on and off the bed, and adjusting the center of gravity of the wheelchair when passing through the threshold and small steps. The front and rear two wheels of the linkage six-wheel mechanism are driven by independent motors, and the middle wheel is driven by a single motor. Among them, the connecting rod and the worm gear located in the middle of the wheelchair drive the gear transmission, so as to adjust the angle of the bottom connecting rod to adjust the overall height of the wheelchair, so as to facilitate the elderly to place and take items at home. At the same time, the worm gear is driven by the worm gear to rotate so as to realize the control of the linkage type six-wheel mechanism on the gear, so that the combination wheel at the bottom of the wheelchair can freely adjust the angle. By controlling the cross angle of the connecting rod and the combination wheel, the overall height of the wheelchair can be adjusted, and the flexible combination theory structure can realize the functions of crossing small steps and barricades including sidewalks and thresholds, and adapting to steep and uneven terrain. At the same time, the horizontal transmission structure located at the upper layer of the layered transmission mechanism drives the lead screw to rotate through the lower motor when crossing the obstacle, so as to drive the sliding block located at the bottom of the seat board to move longitudinally, thus driving the upper part of the wheelchair and the elderly to move forward as a whole to achieve the purpose of balancing the center of gravity.