The cement mortar is dark gray and black, while the mixed mortar is whitish with lime compound. The cement mortar is suitable for underwater engineering and is mostly used in wet environments. The cement mortar is used for general construction projects; the mixed cement mortar is used for cement mortar. Based on the addition of lime, clay and other additives, the mixed cement mortar has strong plasticity and is easy to operate; the cement mortar has less lime paste than the mixed water machine mortar, and the strength is not high.