The invention discloses baking-free hollow thermal insulation blocks and a preparation method thereof. The baking-free hollow thermal insulation blocks are characterized by being prepared from the following raw materials in part by weight: 100 to 115 parts of waste ceramsite, 110 to 130 parts of cement, 90 to 100 parts of flyash, 23 to 27 parts of pearlstone, 190 to 210 parts of mountain flour, 170 to 190 parts of rive stone, 170 to 190 parts of river sand and 39 to 41 parts of water. Waste ceramic is adopted to be prepared into the waste ceramsite to replace partial natural sandstone, and the flyash replaces partial natural sand and cement, so that the damage to natural resources is reduced. The pearlstone is adopted to serve as fine aggregate of concrete to regulate the porosity of mortar and improve construction workability. The product has good mechanical properties and durability, also has good thermal insulation property, improves the thermal insulation capacity of buildings, and is suitable for various thermal insulation projects. The use and construction of the baking-free hollow thermal insulation blocks are same as that of a common block construction method. The technical scheme has the advantages that: the process is easy to operate, the raw materials are readily available and cheap, the production cost is lower, and the economic and social benefits are better.