In order to solve the problem that large items are not convenient to be carried under the condition without elevator,an electric auxiliary stair climbing machine based on the slider-crank mechanism is designed,in which 24 V lithium battery is used as the power supply and a decelerating motor is used as power output mechanism of the stair climbing machine. The optimization of slider guide inclination is analyzed by using motion of UG software. Through the experiment of the physical prototype,the distance difference between the slider movement between the highest point and the lowest point is 17. 674 cm,which meets the coordination standard of the building staircase module of our country. The analysis of ANSYS shows that the strength meets the stress requirements during the movement of the stair climbing machine,the stair climbing machine can run smoothly on the stairs,the safety and reliability of the stair climbing process will be ensured through the mechanical structure.