The invention relates to an elasto-plastic 
well cementing cement slurry and a preparation method thereof, which belongs to the field of gas 
well cementing. The elasto-plastic 
well cementing cement slurry comprises the following components in parts by weight: 100 parts of 
cement, 0-40 parts of a high-temperature stabilizing agent, 0-200 parts of a density adjuster, 4-10 parts of a filtrate loss 
reducer, 0-3 parts of a dispersing agent, 0-2.5 parts of a 
retarder, 35-110 parts of water, 0.2-0.5 part of a defoaming agent, 3-12 parts of a 
plasticizer, and 5-8 parts of a nano filler. The elasto-plastic well cementing 
cement slurry can improve the bending resisting strength and the 
impact resisting strength of the cement stone and reduce the 
elastic modulus of the cement stone. Under high temperature and 
high pressure, the brittle deformation of the elasto-plastic well cementing 
cement slurry is converted into the plastic deformation, thus the later exploitation is guaranteed, and the service life of the oil-gas well is prolonged.