Abstract: After geobelt is included into soil to provide lateral confinement through geobelt-soil interface friction under loading, the modulus ratio of the reinforced cushion to the underlying soft soil stratum increases, the stress distribution capacity of reinforced cushion is strengthened, the bearing capacity of soft soil under reinforced cushion can effectively function, and the foundation settlement decreases. The measurement of soil pressure under reinforced cushion is carried out based on different reinforcement parameters. The test results show that the soil pressure under reinforced cushion is not even. The stress under reinforced cushion concentrates on the edge of foundation, and the stress in the center is less than that at the foundation boundary. The reinforced foundation strength and deformation are relevant with the reinforcement parameters. The stress diffusion capacity of reinforced cushion is analyzed by stress diffusion coefficient under different reinforcement parameters. The reinforcement mechanism can be described as follows: the interface frictions function between the geobelt and the soil, the friction force direction continuously changes, and the stress spreads to the both sides. Based on the practical conditions of the project, the design diffusion angles are put forward for Taiyuan city.