Based on the risk removal and reinforcement project of the clay core wall dam of the Chetianjiang Reservoir, a numerical model of pulsating grouting for clay core wall dam was established using the basic theory of fluid-solid coupling. The influence of pulsating grouting parameters such as pulsating grouting pressure, grouting time and grouting frequency on the stress and strain of clay core wall dam under the impounding condition was simulated and analyzed, and compared with the results of field grouting test. The results show that the stress and displacement of the dam increase with the increase of pulsating grouting pressure, grouting time and grouting duration, and decrease with the extension of grouting interval. When the pulsating grouting pressure ranges from 0.5 to 1.5 MPa, most of the dam body is under pressure and the force is relatively uniform. Affected by the upstream water pressure, the horizontal displacement of the upstream dam is smaller than that of the downstream dam. When the pulsating grouting pressure ranges from 0.5 to 1.5 MPa, the grouting time ranges from 1 200 to 1 800 s, the grouting duration ranges from 7 to 9 s, and the grouting interval ranges from 3 to 5 s, it is beneficial to improve the deformation control of the dam body by the pulsating grouting under the impounding condition, so as to effectively improve the stability of the dam body during the pulsating grouting process.