The invention relates to a thermosensitive expansible shape-memory lost circulation material. The thermosensitive expansible shape-memory lost circulation material comprises a polymer, an auxiliary reactant and a foamer. A preparation method for the thermosensitive expansible shape-memory lost circulation material comprises the following steps: subjecting the polymer and the auxiliary reactant toa reaction, so as to obtain a shape memory polymer; foaming the shape memory polymer, so as to obtain shape memory polymer foam; subjecting the shape memory polymer foam to secondary shaping through aphysical-pressurizing volume compression method; and subjecting the secondary-shaped shape memory polymer foam to crushing granulating, and then, carrying out screening, thereby obtaining shape-memory lost circulation material particles of different initial particle sizes. An application method for the thermosensitive expansible shape-memory lost circulation material comprises the steps: adding the shape-memory lost circulation material into drilling fluid in a manner that the dosage is 1%-5% the mass of the drilling fluid, carrying out uniform stirring to form lost circulation slurry, injecting the lost circulation slurry into a loss zone through a drilling fluid pump, carrying out pulling out, and then, carrying out well shutdown pressurizing until the pressure is 2MPa to 5MPa, therebycompleting leakage stoppage. According to the thermosensitive expansible shape-memory lost circulation material, the preparation method and the application, disadvantages of the traditional inert lostcirculation materials and water absorption expansion type resin particulate materials can be overcome, and the success rate of on-site leakage prevention and stoppage of oilfields is increased.