An eight shot pellet injector is used to fuel the HL-1M tokamak from the low field side. The pellet ablation process is investigated witha CCD camera and an array of Hα emission detectors. It isobserved that the velocity of the pellet ablation cloud is obviouslyslowed down after it enters the plasma. The ablation clouds areelongated along the magnetic field direction. By means of multi-exposures with theCCD camera during pellet ablation, the safety factor profile isestimated with the ablation cloud inclination angles with respectto the torus on HL-1M. The pellet penetration depth is analysed withAbel inversion of the Hα emissions. The result is compared with theprediction of ablation models. Kuteev's model is more suitable fordescribing pellet ablation processes in the HL-1M plasma than the neutral gasshielding model.