Abstract: Preconditioned AUSM+(advection upwind splitting method+) scheme was discussed in details and was applied to numerical simulation of multi-component chemical reacting flows at all speeds.Based on multi-component Navier-Stokes equations with time-derivative preconditioning, an effective algorithm for simulating the reacting flows over a wide range of Mach numbers was developed using the preconditioned AUSM+ scheme.Numerical experiments, including supersonic flow, subsonic flow and low speed flow, show that the algorithm can be applied efficiently to the reacting flows at all speeds.