The invention discloses high-ductility thermal insulation mortar. The high-ductility thermal insulation mortar is prepared from the following components in parts by weight: 20-100 parts of cement, 0-80 parts of a mineral admixture, 5-40 parts of high-strength microbeads, 0-35 parts of aggregate, 10-50 parts of an acrylate copolymer emulsion, 5-30 parts of water, 1-1.5 parts of a water reducer, and0.75-6 parts of fibers. An air entraining material or prefabricated bubbles do not need to be added, and the bubble content and dry density of the thermal insulation mortar are adjusted by adjustingthe rotating speed and stirring time of a stirrer; the prepared high-ductility thermal insulation mortar is small in dry density fluctuation amplitude, the high-strength microbeads are evenly distributed and do not float, the deviation of the actually-measured air content and the designed air content of the mixture is small, and the dispersion coefficient of the fibers is high; the mortar is highin ductility, high in deformation capacity, low in thermal conductivity coefficient, high in compressive strength and high in bonding strength with a base body; a preparation process is simple and convenient, and the raw materials are wide in source; and the high-ductility thermal insulation mortar disclosed by the invention can be applied to thermal insulation of wall bodies and roofs, thermal insulation of the surfaces of concrete dams in severe cold regions and the like.