The invention relates to an imitated bowlder artificial flagstone which is prepared from the following components in parts by weight: 60-80 parts of aluminum hydroxide, 20-25 parts of composite powder, 71-82 parts of water reducing agent, 1-3 parts of accelerant, 0.2-0.3 part of potassium peroxide aceton, 28-32 parts of unsaturated polyester resin, 24-45 parts of ash gravel, 0.1-0.3 part of pigment paste, 0.1-0.8 part of alloyed powder, 20-40 parts of glass fiber, 36-50 parts of loess lime powder and 0.35-0.5 part of auxiliaries. The invention has the advantages that the stone formula is prepared according to a modern production technology on the basis of a polymer composite material selected for patterning the imitated bowlder, the imitated bowlder artificial flagstone is environmentally friendly, non-toxic and radiation-free and is a new generation environment-friendly building product, and the product has various patterns, bright color and crystal clear appearance and the product can be produced according to various requirements of the clients, is flexible and convenient for decoration and is capable of creating colorful life space.