Abstract: Different mole ratio of AMPS/NNDMA binary linear copolymer fluid loss reducer and PCE dispersant as the main additives, the oil well cement slurry filtration resistance, rheology, thickening, the influence of consolidation are studied.The results show that the AMPS/NNDMA copolymer under little amount can effectively control the slurry filtration performance and free fluid content. Fluid loss reducer made the bad slurry rheological property, the dispersant can greatly improve the rheological property. With high temperature and high pressure thickening the consistency of cement slurry and thickening time, experiments show that additive offers certain retarding action and adjustable thickening time. By cement compressive strength test, the results show that under the reasonable dosage, cement strength also satisfies the requirement of construction. The increasing of NNDMA in the fluid loss additive reduces water loss and free fluid content, increases the consistency, and leads the poor rheology and strength of cement. In addition, the two additives have good thermal stability and heat resistance &salt resistance.