The invention relates to a method for extracting 
indium and preparing 
iron oxide by 
slag-free 
zinc hydrometallurgy of 
zinc concentrate, which comprises the following steps of: 1, performing 
fluidized bed roasting, neutral leaching, low acid leaching, purification and electrodeposition on the 
zinc concentrate to prepare electric zinc; 2, performing high acid leaching, reduction, preneutralization and displacement to remove 
copper on low acid leaching residue and waste 
electrolyte after the electrodeposition to prepare the electric zinc; 3, neutralizing the liquid from which the 
copper is removed to settle the 
indium; 4, vulcanizing the liquid in which the 
indium is settled to remove heavy 
metal and then adding 
lime milk to neutralize the liquid to obtain deeply purified liquid; 5, 
settling iron in the deeply purified liquid by a hydrothermal method to obtain 
hematite powder; and 6, removing impurities from the 
hematite powder to obtain soft magnetic 
iron oxide. In the method, the indium is settled by neutralizing and the iron is settled by the hydrothermal method, so that the indium is separated from the iron, the indium is separated from the zinc, the 
hematite powder is formed, and the requirement of the soft magnetic 
iron oxide is met through 
impurity removal treatment. The method has the advantages of simple process, high 
recovery rate of the indium and the zinc, short flow for separating the iron from the zinc, high purity of the iron, environmental friendliness, suitability for industrial application, and capability of replacing the conventional 
slag-free zinc 
hydrometallurgy process for extracting the indium and making effective use of the iron resource in the zinc concentrate in a form of the soft magnetic iron 
oxide.