Aiming at the problems of long horizontal section， complex wellbore conditions， difficulty in casing centralization， low displacement efficiency， and high performance requirements of cement system which restrict the improvement of cementing quality in shale oil horizontal wells， research on the collaborative optimization technology of drilling parameters and drill string assembly was carried out to meet the requirements of improving cementing quality for wellbore cleaning. In addition， the ideal casing centralization is designed by the simulation of displacement efficiency， and the integral stamping screw semi-rigid centralizer and the water displacement prestressed cementing technology are also optimized. Furthermore， the strength of cement paste is improved based on the toughness modification technology. The hydraulic fracturing requirements of shale oil wells can be met through ruducing the Young''s modulus and using the improved cement paste. All these work ensured the cementing quality of Well GY5-1-4H， so as to provide a worth considering key technology for long horizontal well cementing.