To study the influence of crucial parameters on the treatment effectiveness of soft subgrade in the squeezed branch piles-ground beam reinforcement system, a three-dimensional finite element model was established and fully verified based on the engineering practical of Shantou Ring Express. Furthermore, orthogonal experimental method was adopted to conduct sensitivity of four factors of pile diameter, pile spacing, pile length and ground beam thickness. The results indicate that there are significant differences in the sensitivity of different factors in the reinforcement system of support piles. The factors that are more sensitive to the maximum settlement are pile length, pile spacing, and pile diameter, while the factors that are more sensitive to the load sharing ratio are pile spacing. In addition, changes in pile length and diameter significantly affect the variation of the maximum settlement value, but their impact on the load sharing ratio is not prominent. Therefore, a reasonable value should be determined based on comprehensive settlement control and economic requirements. The relatively dense spacing between support piles did not significantly improve the two test indicators, and the actual design can be taken as 4.0 ~ 4.75 m. The thickness of the ground beam is not the dominant control factor for settlement and load sharing indicators. It is recommended to prioritize 0.5 ~ 0.6 m without reinforcement constraints.