Abstract: Zhou 57 is a complex block thin layer reservoir,block faults,water distribution complex and developing lots of oil - water layer,have a great impact on the development of horizontal well.With geological data,combined with the actual production data of horizontal well,we analysed the block distribution of oil and water layers,and then studied the relation between oil-water layer and the water production rate by using numerical simulation,established the appropriate level of water production rate and water saturation interpretation chart,finally gave the corresponding technological counter measures of horizontal well development adjustment in oil-water zone.