The invention discloses a method for preparing
polyolefin by
metal-catalyzed ring-opening metathesis
polymerization, which comprises the following steps: (1) dissolving
norbornene monomers in a
solvent to prepare a
monomer solution A; (2) dissolving a
Grubbs catalyst in a
solvent to prepare a catalyst solution B; and (3) in a microchannel reaction device, simultaneously pumping the
monomer solution A and the catalyst solution B into a
microreactor provided with a spherical internal component, reacting, collecting a reaction solution, separating and purifying to obtain
polyolefin. According to the invention, the sphere is placed in the
microreactor as an internal component, so that Poiseuille flow in the pipeline is effectively improved, the
mass and
heat transfer efficiency is improved, the
polymerization rate is increased, the space-
time control of the reaction in the pipeline is enhanced, and the high-molecular-weight narrow-distribution
polyolefin is efficiently prepared. Meanwhile, a brand new thought is provided for
polymerization reaction
process control, and the method has important industrial application value.