A polyimide-epoxy blend has been prepared by reacting epoxy resin with imide compounds containing carboxyl groups at the ends of the molecular. When coated on the silicon steel sheets, the blend can be used as a kind of adhesive to bind together the silicon steel sheets of aerospace electrical machineries. Put pressure of 0.4-0.5MPa on a stack of coated silicon steel sheets, and cured at 200°C for 2 hours, binding course of 0.01- 0.02mm on the sheets was formed. Tensile shear strength of the binding course on stainless steal substrate is greater than 23MPa at room temperature, 8MPa at 200°C. After enduring in air at 300°C for 48 hours the tensile shear strength at room temperature remained 17MPa, dipping in aerospace lubricant at 250°C for 48 hours remained 18 MPa, steeping in dimathylacetamide at 160°C for 12 hours remained 12 MPa.