The present invention discloses a high-efficiency, stable polishing and grinding device, the transmission system and the lubricating system of which are characterized by simplicity, reliability, convenient maintenance and low failure rate. The polishing and grinding device is composed of a turnplate-revolving mechanism, a turnplate-lifting mechanism and multiple groups of high-speed rotating grinding mechanisms mounted on a turnplate; wherein, each high-speed rotating grinding mechanism is composed of a roller type grinding head, a grinding head motor and driving mechanisms thereof; the roller type grinding head is mounted on the lower side of the turnplate; the grinding head motor is mounted on the upper side of the turnplate; through a group of driving mechanisms, the grinding head motor drives the roller type grinding head to rotate at a high speed. The polishing and grinding device is mainly applied to the polishing and grinding of the surfaces of flat building materials such as polished ceramic tiles and stones.