In the golden autumn season, laurel fragrance. In this harvest season, the company has successfully developed a new type of three fold portable multi-functional bicycle (has applied for invention patent). The new bicycle uses transmission shaft instead of chain transmission. The faucet, handle and seat frame can be adjusted and retracted, and the front fork, rear fork, frame and transmission shaft can be folded. Adjust the appropriate size along the axial direction when retracting and folding. When folding, one fold, two fold and three fold can be carried out according to the folding mechanism when folding. The bicycle can reach the minimum dimension after shrinking and folding, which can be dragged, portable and used as a seat. The new bicycle is compact in structure, small in size, light in weight, easy to carry, economical and practical, which will be deeply environmental friendly for all kinds of people.