Transmission device high in transmission power and transmission efficiency and capable of replacing speed reducer

The invention discloses a transmission device high in transmission power and transmission efficiency capable of replacing a speed reducer, and the transmission device is composed of a transmission chain, a chain wheel, transmission shafts and bearings, wherein a coaxial transmission device is formed by at least two bearings which are arranged on each transmission shaft and a rod body of a shaft rod in a matched manner; all the bearings are fixedly arranged in a positioning manner; and a prime mover outputs rotating power to a working machine through a transmission chain, a chain and N coaxial transmission devices. The transmission device has the advantages of simple structure, convenience in assembly, flexibility in dismounting, easiness in maintenance, high transmission power and high transmission efficiency.