The management of thoracolumbar (TL) burst fractures remained challenging. Due to the complex nature of the fractured vertebrae and the lack of clinical and biomechanical evidence, currently, there was still no guideline to select the optimal posterior fixation strategy for TL burst fracture. We utilized a T10-L3 TL finite element model to simulate L1 burst fracture and four surgical constructs with one or two-level suprajacent and infrajacent instrumentation (U1L1, U1L2, U2L1, and U2L2). The present study was aimed to compare the biomechanical properties and find an optimal fixation strategy for TL burst fracture in order to minimize motion in the fractured level without exerting significant burden in the construct. Our result showed that two-level infrajacent fixation (U1L2 and U2L2) resulted in greater motion reduction ranging from 66.0 to 87.3 precents compared to 32.0 to 47.3 percents in one-level infrajacent fixation. Flexion produced the largest pathological motion in the fractured level but the differences between the constructs were small, all within 0.26 degrees. Comparisons in implant stress showed that U2L1 and U2L2 had an average 25.3 and 24.8 percent less von Mises stress in the pedicle screws compared to U1L1 and U1L2, respectively. The construct of U2L1 had better preservation of physiological motion while providing sufficient ROM reduction at the fractured level. We suggested that U2L1 was a good alternative to the standard long-segment fixation with better preservation of motion and without an increased risk of implant failure.