The crushing and grinding system is a very important link in the concentrator, and its engineering cost directly affects the economic benefit of the whole project. Aiming at the typical " three sections and one closed circuit" process flow of mineral processing industry projects. This paper studies the engineering cost of the crushing and grinding system of multiple mineral processing projects, statistically analyzes the construction investment estimates of each individual project of the crushing and grinding system of different projects, summarizes the investment estimation indicators of the corresponding individual projects. It provides a basis for stakeholders or design consulting units to estimate the investment of grinding system in similar mineral processing projects in the future. It also provides a reference for construction units to estimate the investment of grinding system in concentrators with similar processes.