AIM:To discuss the effectiveness and techniques of vitrectomy using binocular indirect ophthalmomicroscope(BIOM3).METHODS:A retrospective study was carried on 126 patients(126 eyes) which were performed vitrectomy under BIOM3.The operation time,techniques of equipment using,intraoperative complication,postoperative visual acuity(VA) and complication were observed.RESULTS:Operation time was 44-92(mean 55) minutes.The postoperative follow-up time ranged from 3 to 10(mean 4.5) months.The postoperative visual acuity improved in varying degrees:VA≥0.3 in 12 eyes,0.3>VA≥0.1 in 36 eyes,0.1>VA≥0.01 in 45 eyes,VA<0.01 in 33 eyes.There was no severe complication during operation.5 retinal re-detachment cases,7 anterior chamber haemorrhage cases,5 secondary glaucoma cases and 2 proliferative vitreoretinopathy(PVR) cases were observed in follow-up after operation.BIOM3 application skills were introduced.CONCLUSION:We can get a good visualization and a wide field of retina in aphakia,gas-filled or silicone-filled eyes,small pupil and corneal diseases under BIOM3.BIOM3 is an excellent vitreoretinal surgical equipment with wild-angle viewing field and assistant-friendly advantages.