The invention relates to a heat-preservation and heat-insulation crack-resisting brick made from modified vitrified micro beads and effectively resolves the problems of large contractibility rate, poor stability, easy cracking and high cost of masonry walls. According to parts by weight, the brick is composed of the following raw materials: 100 parts of cement, 5-20 parts of coal ash, 0.005-0.015 part of polypropylene fiber, 10-50 parts of modified vitrified micro beads, 10-30 parts of activating agent, 1-5 parts of sodium silicate, 10-50 parts of sand, 10-200 parts of fine stone and 110-330 parts of water. The method for preparing the brick comprises the following steps: evenly stirring and mixing the modified vitrified micro beads, 50 parts of the cement and the activating agent to form material A, then evenly stirring and mixing the fine stone, the sand, the coal ash, the polypropylene fiber and the remaining 50 parts of cement to form material B; adding water to stirring the material A and material B into uniform brick material; pressing the brick material into block-shaped bricks by a die and curing the block-shaped bricks at 10-40 DEG C for 7-30 days, thus obtaining the final product. The brick of the invention features scientific and reasonable components, simple process, stable quality, low contractibility rate, low coefficient of heat conductivity, good heat-preservation and heat-insulation property, low cost, environmental friendliness, economy and tremendous economic and social benefits.