The invention relates to an oil-water separation device, and especially relates to an oil-water separation device used for separating oil and water with micro-interface fiber. The oil-water separation device is mainly used for solving technical problems in the prior art that oil water separation treatment effect is poor, operation is unstable, secondary environment pollution is caused, equipment investment and maintenance cost is high, occupied area is large, processing speed is low, and economical benefit is low. The oil-water separation device comprises an oil removing front oil groove (1); the oil removing front oil groove (1) is connected with an ultrafilter (3) via an oil removing pump (2) and a pipeline; the ultrafilter (3) is connected with a micro-interface oil water separation tower (4); the micro-interface oil water separation tower (4) comprises a tower body (5); more than two layers of perforated plates (6) are arranged in the tower body; micro-interface fiber layers (7) are arranged on the perforated plates; a water outlet pipe of the micro-interface oil water separation tower is connected with an inclined plate clarification groove (8); an inclined plate layer (9) is arranged in the inclined plate clarification groove; a water outlet pipe of the inclined plate clarification groove is connected with a low level storage tank (10); and the top of the micro-interface oil water separation tower, and the top of the inclined plate clarification groove are communicated with a backwash liquor storage tank (11).