The invention relates to a technology for preparing cement by a dry carbide slag method, which comprises the following steps: raw material storage, transportation, mixture, calcinations, grinding, and the like. Dry carbide slag powder with the moisture from 5 percent to 8 percent, which is discharged by a dry acetylene technical generator, is sealed, transported and stored by a pipe chain machine and a bucket lifting machine; stored raw materials and black raw materials ground in a drying process comprise aeolian sand, sulfate slag and lime slag; carbide ash is transported to a dry pipe by an FU chain transporting machine for initially mixing and drying after being automatically matched and ground by a reservoir bottom microcomputer; raw materials with the moisture which is less than 1 percent are collected by a high-efficiency cyclonic collector and are transported to a raw material homogenizing storehouse to mix by gravity; the raw materials are calcined from a three-grade preheater and a decomposing furnace to a rotary kiln; and after the raw materials are cooled, the raw materials, fly ash, carbide ash and citric acid slag are transported to a cement mill to grind after being metered by a speed-regulating constant feed weigher. The technology increases the participation quantity and the economic benefit of the carbide slag, reduces the environmental pollution and the resource waste, can be used by combining the dry acetylene producing technology and the traditional technology and can be singly used.