Preparation method of hexafluoropropylene oligomer

The invention relates to the technical field of fine chemical engineering, and discloses a preparation method of a hexafluoropropylene oligomer, which comprises the following steps: mixing and stirring an ionic liquid YX theta and a dipolar aprotic polar solvent to prepare a catalyst solution; carrying out preheating treatment on the micro-channel reaction module; adding a catalyst solution and hexafluoropropylene gas into the preheated micro-channel reaction module, and reacting; and after the reaction is finished, separating the effluent of the micro-channel reaction module to obtain the hexafluoropropylene oligomer at the lower layer. The catalyst solution prepared from the ionic liquid with specific components and the dipole aprotic solvent is green, environmentally friendly and low in toxicity, and does not need to be added with extra expensive catalysts and auxiliaries; meanwhile, the prepared hexafluoropropylene oligomer not only has high conversion rate and high selectivity, but also can be selectivel