A technological process for preparing active powder concrete by using iron tailing is characterized by performing screening and mechanical-chemical activation to iron tailing, using partial iron tailing after screening as fine aggregate of the active powder concrete, using activated tailing as component of the active powder concrete, and preparing the active powder concrete. The invention substitutes partial cement, quartz powder and silica fume with mechanically-activated iron tailing and fly ash or slag, and quartz sand or river sand with screened iron tailing fine aggregate, and prepares high-strength active powder concrete under standard curing or high-temperature high-pressure curing condition; and compared with conventional method, the invention reduces raw material cost, improves iron tailing comprehensive utilization rate, reduces natural resource consumption amount, and promotes development of ecological environment protection and circular economy promotion.