Preparation method of bisphenol F type low-chlorine low-viscosity epoxy resin

The invention provides a preparation method of bisphenol F type low-chlorine low-viscosity epoxy resin, and belongs to the technical field of resin preparation. The method comprises the following steps: 1) under the protection of nitrogen, mixing and stirring bisphenol F and epoxy chloropropane, dissolving, adding an alkali solution, diethylene glycol dimethyl ether and 1, 4-dioxane, and carrying out a ring-opening reaction to obtain an intermediate chlorohydrin ether; 2) in a vacuum environment, dropwise adding an alkali solution into the reaction system of the intermediate chlorohydrin ether to carry out closed-loop dehydration; 3) after the closed-loop dehydration is finished, carrying out reduced pressure distillation; 4) after the reduced pressure distillation is finished, adding an alkali solution, and carrying out a refining reaction to obtain an epoxy resin crude product; and 5) sequentially performing dissolution, water washing and molecular distillation on the epoxy resin crude product to obtain the