The invention belongs to the technical field of building materials and relates to an environment-friendly paving building material. Algae-residue combustion ash paving bricks are prepared by the following raw materials in percentage by weight: 40 to 60 percent of algae-residue combustion ash, 30 to 50 percent of river mud or flyash and 10 percent of fine aggregate. The raw material of the algae-residue combustion ash paving bricks is the algae-residue combustion ash, the doping amount is large and the problem of algae-residue treatment is better solved. The algae-residue combustion ash replaces clay, so that land resources are saved, the waste is changed into treasure, the social, environmental and economic benefits are good, and the national environmental protection policy of saving energy and reducing emission is followed.