The utility model provides a grinding device of a flat layer and a surface layer. The grinding device comprises a roller and a driving support, wherein the roller is connected with a hollow steel barrel in a sleeved mode, the hollow steel barrel is connected with a center shaft in a sleeved mode, the roller is of a hollow structure, and the inside of the roller is communicated with the hollow steel barrel which is provided with a sand filling opening communicated with the hollow portion of the hollow steel barrel; and the driving support is provided with a scraping plate parallel with the roller. In construction, certain amount of sand is filled in the hollow steel barrel and the roller communicated with the hollow steel barrel from the sand filling opening, then the sand filling opening is well covered, a construction operator pulls a driving handle sleeve on the driving support to drive the roller to grind repeatedly on a concrete face until concrete cement paste is extracted, and the scraping plate fixed on the support can effectively wipe out the concrete adhered to the roller in a scraping mode. After the construction, the sand in the roller is poured out from the sand filling opening, transportation is benefited, operation is simple, and the grinding device is economical, energy-saving and environment-friendly.