报道了在实验条件下热晕小尺度不稳定性的研究结果．从实验及数值模拟两方面给出了光束质量Ｓｔｒｅｈｌ比，扰动积分能量的增长，各扰动谱项的能量竞争以及近场光斑半径随时间的变化．研究结果基本反映了热晕小尺度不稳定性的物理规律．实验测量与数值计算的结果具有较好的一致性． The results of a small scale thermal instability study under experimental conditions are reported. The Strehl ratio of the beam quality, the increase of the integral energy of the perturbation, the energy competition of each perturbation spectrum term, and the change of the spot radius of the near field over time are given from the experiments and the numerical simulations. The results basically reflect the physical laws of small-scale instability of thermal halo. The experimental measurements and numerical results have good agreement.