Abstract: Slurry curing is one of the key parts of cementing process. The quality of slurry curing directly impacts the cementing quality, and then impacts the quality and cost of the whole drilling project. With the slurry curing, the pressure of slurry column would decrease, and it leads to the tension increase of the top casing, which is the main issue that causes the crossflow of oil, gas, or water, and also the early breakdown of casing. The experimental equipment was designed for testing casing load during the process of slurry curing. Through the simulation in different downhole conditions, it was studied that the impact of slurry density, cement length, addition agent, and reservoir property on the tension of the top casing. The rule was drawn that the casing axial tension would increase early and then decrease, and finally get stable, with the increase of the slurry curing period. The study could be a reference for the composition selection of slurry system and the improvement of slurry injection technique.