The invention discloses a natural solid cleaning agent for cleaning stains on hard surfaces of objects, which is prepared from the following raw material in percentage by weight: 6 to 50 percent of kaolin, 4 to 36 percent of zeolite, 7 to 45 percent of calcite powder, 3 to 40 percent of pumice powder, 4 to 55 percent of feldspar powder, 2 to 17 percent of kieselguhr, 3 to 22 percent of montmorillonite powder, 4 to 40 percent of talcpowder, 1 to 15 percent of saponin, 3 to 18 percent of white carbon black and 0 to 40 percent of water. The natural solid cleaning agent has desirable cleaning effect on various stains, such as oil stains, sweat stains, tea stains, juice stains, milk stains, blood stains, ink stains, ash stains and dust stains on hard surfaces of metal, ceramic, wood, glass, fiber plates and stone plates. The raw materials are natural powder and plant extracts. The cleaning agent has high biodegradability and is safe, environmentally-friendly, pollution-free and convenient to use.