This paper investigates the bending collapse characteristics of thin double-walled multi-corner columns (TDWMCC) under side impact loading by using numerical simulation and experimental verification. The finite element model of TDWMCC under lateral impact loading was established and analyzed using the nonlinear finite element code LS-DYNA. The TDWMCC consist of two walls of similar thickness, spaced 2–6 mm apart. To fix the inner and outer walls of columns, two methods were introduced: two plates were added at both ends of the column and several ribs were placed between the walls. The impactor moved at a constant velocity to punch the TDWMCC in a three-point bending model. Firstly, depending on the distance between the inner and outer walls, the FEM results indicate that TDWMCC exhibited increases in peak force by 47.2–48.6%, total energy absorption (EA) by 51.6–54.1%, and specific energy absorption (SEA) by 7.07–20.1% in comparison with the single-walled multi-corner columns. Secondly, the effect of the ribs between the inner and outer walls on impact characteristic of TDWMCC was also analyzed. Utilization of both middle ribs and corner ribs resulted in higher energy absorption capability compared to TDWMCC without ribs. Among two types of ribs, corner ribs perform better with their EA being 1–2% higher than that of middle ribs. Thirdly, the distance between the inner and outer walls and its effect on lateral impact resistance were also considered. For both methods, whether using ribs or end plates, a wall distance of 4 mm was found to be optimal for maximizing bending energy absorption capability. Finally, the experiments showed good agreement with the numerical results not only in bending collapse process but also in impact force, and energy absorption capability of TDWMCC during lateral impact. These findings contribute to the design of energy-absorbing structures in engineering applications where side impact is a critical concern.