The invention discloses a well cementation cement sheath simulation sample, a preparation method and a performance testing device and method thereof, and belongs to the technical field of well cementation performance evaluation. The sample comprises a sample body, a sleeve and a cement sheath. The preparation method of the sample comprises the steps of preparing the sample body, selecting the sleeve, drilling a blind hole in the body, arranging the sleeve in the blind hole, filling the annular containing space with cement paste, performing maintaining and obtaining the sample. The testing device comprises the sample, a real triaxial loading chamber, a hydraulic tube, a hydraulic servo system and a flaw detection device. The testing method comprises the steps of assembling the testing device, starting the hydraulic servo system, obtaining the sample obtained after hydraulic fracturing is performed, taking out the sample obtained after hydraulic fracturing is performed, knowing a wound of the sample obtained after hydraulic fracturing is performed, analyzing the wound, and according to the analysis result of the wound, evaluating the performance of the cement sheath. According to the well cementation cement sheath simulation sample, the cement material mechanics performance can be evaluated, the better well cementation cement material is selected, and technical references are provided for ensuring production safety of an oil and gas well.