Polyimide modified epoxy resin and application thereof

The invention discloses polyimide modified epoxy resin and application thereof, raw materials of the polyimide modified epoxy resin comprise polyimide and epoxy resin, the polyimide is double-terminated polyimide with a softening point less than or equal to 70 DEG C and a molecular weight of 1000-5000, and the epoxy resin is epoxy resin. The double-terminated polyimide is prepared from the following raw materials: bismaleimide, a double secondary amino compound, a boron nitride nanosheet containing a vinyl-terminated chain segment and hydroxystyrene, the carbon number of the vinyl-terminated chain segment is greater than or equal to 3, and a group connected with vinyl is methylene or methylene; the preparation method of the polyimide modified epoxy resin comprises the following steps: carrying out ring-opening reaction on a terminal hydroxyl group of double-terminated polyimide and an epoxy group of epoxy resin, and the polyimide modified epoxy resin has the advantages of long service life, good thermal condu