Due to the degradation of leg bone function, the elderly people have difficulty in walking and bending down. Based on the analysis of the current situation of mobility assistance products and the usage needs of the elderly, innovative design was carried out by using TRIZ theory. By analyzing the principles of innovative inventions and finite element simulation to calculate structural strength, and referring to ergonomic human body size data, a walking aid device for the elderly has been developed. Testing and applying the device model shows that this device can better meet the usage needs of the elderly and improve their living standards. Compared to the multi-functional crutch products on the market, the device has functions of adjustable extension, support mode conversion, picking up objects, assisting users in standing and walking. It can solve the problem of inconvenient walking and inability to bend down to pick up objects for the elderly.