Abstract: According to the requirements of high resolution and high bandwidth on moving mirror supporting mechanism in Fourier transform infrared (FTIR) spectroscopy. A moving mirror supporting mechanism was designed by parallel leaf springs. First, the characteristic of parallel leaf springs was analyzed; and then, the design basis of moving mirror supporting mechanism was presented by theory analysis. Dynamical response and static response were computed with the finite element method. Meanwhile, calculation results were compared with parallel two beam moving mechanism. The results show that the first order natural frequency is 244.79 Hz, the parasite displacement perpendicular to moving direction is 0.611 m when moving displacement is 14 mm, the maximum stress value is 131 MPa. The conclusion is that this mechanism has better performance than two beam moving mechanism and the study lay a good foundation for future research through the theoretical analysis and the numerical simulation.