The invention discloses a magnetic-red mixed lean iron ore pre-concentration technology and belongs to the field of iron ore concentration. The magnetic-red mixed lean iron ore pre-concentration technology includes the following steps that a, magnetic-red mixed lean iron ore is broken into -12 mm fine ground products through three sections and one closed loop; b, the fine ground products are subjected to wet type linear screen screening, and two fractions of -12+3 mm and -3 mm are obtained; c, the -3 mm fraction products are subjected to intermediate magnetic separation, intermediate magneticseparation tailings are subjected to strong magnetic separation, strong magnetic separation tailings are classified through a screw classifying machine, and intermediate magnetic separation concentrates and strong magnetic separation concentrates are merged, dewatered and then conveyed into a fine ore bin; and d, the -12+3 mm fraction products are subjected to intermediate magnetic dry separation,intermediate magnetic dry separation tailings are subjected to strong magnetic dry separation, and intermediate magnetic dry separation concentrates and strong magnetic dry separation concentrates are combined and conveyed into the fine ore bin. By means of the magnetic-red mixed lean iron ore pre-concentration technology, the defects that in the prior art, the concentration investment of magnetic-red mixed lean iron ore is large, and difficulty is high are overcome, and the magnetic-red mixed lean iron ore pre-concentration technology is provided and is particularly suitable for treating themagnetic-red mixed lean iron ore with the TFe grade ranging from 20.0% to 30.0%.