The invention discloses a thermal-reversible self-repair polyurethane membrane and a preparation method therefor. Under protection of inert gases, 4,4-diphenylmethane diisocyanate, polycaprolactone glycol and N,N-dimethyl formamide are mixed uniformly, a reaction is carried out at a temperature of 50-60 DEG C, then the solution is cooled to a temperature of less than 5DEG C, 2-furan methylamine is added in the solution, the temperature is risen to 95-105 DEG C, the reaction is carried out for 10-11h, then hyperbranched polysiloxane with maleimide groups is added, the pre-finishing product prepared after the reaction is finished is poured into a die and dried, and a thermal-reversible self-repair polyurethane membrane is obtained. By utilization of the Diels-Alder (DA) reaction, thermal-reversible self-repair of a polyurethane membrane is achieved, the prepared polyurethane membrane has advantages of excellent thermal stability and high hardness, and raw materials have wide sources. The preparation method has characteristics of simple technology, strong practicality, wide applicability and the like.