The objective of the invention is to be achieved through the following technical solutions: Extract the method for iron from slag, comprise following order and step: A, slag is crushed to below 10mm, in the ball mill of packing into, adds in mass ratio CaO 0.1-8.0kg/t and NaOH 0.1-4.0kg/t simultaneously, ore grinding is to-200 orders; B, ore ...