The invention discloses a non-integrated rotating hemisecting saw. A first output shaft is sleeved with a second output shaft and is coaxial with the second output shaft, the second output shaft can rotate relative to the axial direction of the first output shaft, a first ratchet is arranged on the end surface of one end, close to an inner saw blade, of the second output shaft, the inner saw blade is fixed on an inner flange, a second ratchet matched with the first ratchet is arranged on the inner flange, an elastic body is further arranged between the inner flange and the second output shaft, and the inner saw blade is closely attached to an outer saw blade. The saw has the advantages as follows: the ratchet on the second output shaft and the ratchet on the inner flange are flexibly meshed with each other by the aid of the friction force produced by the elastic body, meanwhile, the elastic body axially pushes the inner flange to slightly press and abut against the inner saw blade, and the inner saw blade and the outer saw blade are closely attached to each other, so that problems of collision abnormal noises and vibration of ratchets during matching of existing ratchets are solved, and the problem that saw blades bifurcate easily due to cut materials at the moment that a machine is started when the saw blades make contact with the cut materials before the machine is started is further solved.