In order to develop the low permeability reservoir, the horizontal well with L26-P25 long horizontal section was deployed in Long 26 block of Daqing oil field. Based on the introduction of casing program and design features of well trajectory profile, the difficulties in drilling construction are analyzed and the technical measures adopted in this well are elaborated in detail in well trajectory control, rotary geo-steering drilling technology, friction and torque monitoring, hole cleaning and some other aspects. L26-P25 long well is 4045.00m in total depth and 2033.00m in horizontal section; all the indexes meet the design requirements. It is a record of the longest horizontal section in horizontal well with water-base drilling fluid in Daqing oilfield, the construction experience is accumulated for the same type horizontal well with long horizontal section in future.