Abstract: In order to improve the dressing index and single unit handling capacity of roughing in Pangang Midi concentration plant, in case of the similar ore grade, compared the T-GCTS1230 medium magnetic field intensity magnetic separator with the using CTS1030 magnetic separator of industrial test in single series. The results show that the concentrate grade of test series increased by 1.11%, the tailing grade reduced in 0.54%, the recovery of roughing choose increased by 0.92% and the single unit handling capacity can meet the requirement of 130 t/h. According to the test results, T-GCTS1230 medium magnetic field intensity magnetic separator has been used in Midi concentration plant of 16 series. It is estimated that the economic effectiveness is 1.077 million yuan per year.