Abstract: In order to efficiently develop and utilize low-grade complex refractory iron ore，the wet high intensity magnetic pre-separation test was carried out on the high pressure roller mill product of low�grade siderite ore in Daxigou.The conditions of different magnetic field strength，flushing water volume，rotat⁃ ing ring speed and pulsating stroke were tested respectively. According to the results of the condition test， the best process parameters were selected.The test results show that under the condition of 25.54% iron grade of raw ore，the iron concentrate with yield of 83.65%，iron grade of 27.74% and iron recovery of 90.84% can be obtained by wet high intensity magnetic preconcentration of high pressure roller mill product. At the same time，the coarse tailings with yield of 16.35% and iron grade of 14.31% are thrown out. The effect of discard⁃ ing is better，the amount of ore dressing into grinding is greatly reduced，and the effect of energy saving and emission reduction is obvious. It has reference value for the efficient development of this kind of iron ore.

Key words: siderite, wet pre-concentration, high intensity magnetic separation, high pressure roller mill