X-section cast-in-place concrete pile (XCC pile), as a non-circular sectional special-shaped pile, turned the circular arch into reverse arch based on the principle of constant sectional special-shaped periphery enlargement, to turn the circular arc positive arch into an anti-arch, and finally forms a symmetrical X-shaped section, to expand the section perimeter and improve the bearing capacity. The installation process of XCC piles is actually a process of soil squeezing, and the effect of soil squeezing of pile group penetration is more complicated than that of single pile. However, there is limited research on the effect of soil squeezing of XCC piles group penetration at present, and the effect of soil squeezing of XCC pile group penetration is an important topic in the study of XCC piles. The effects of different pile types and different pile sequences on the squeezing effect of pile group penetration are studied. Based on the transparent soil technique, the penetration test of XCC pile and circular pile group was carried out. The displacement field variation pattern of pile group penetration was obtained via particle image velocimetry, and the influence of different pile types and penetration sequences on squeezing effect of pile group was studied. Results show that obvious cumulative effect and shielding effect can be observed during the penetration of XCC and circular group piles. For the displacement of the soil of the last penetrated pile dorsal surface, the displacement caused by XCC piles penetration reaches the peak first than that of the circular piles, and both XCC piles and round piles penetration produce obvious cumulative effect and shielding effect. The shielding effect of XCC pile is stronger than that of circular pile. Finally, empirical formula for predicting the shielding effect for XCC and circular piles under different penetration sequences was provided.