A multi-phase-field model is applied to simulate the peritectic reaction of Fe-C alloys. The phase-field equations, the diffusion equation for the multi-phase-field model and a dilute solution approximation for the descriptions of the free energy densities are presented. The thin-interface limit of the phase-field model for alloy solidification is employed to obtain the parameters relationship. The calculated results of the peritectic reactions show that the growth rates of the γ phase follow the parabolic growth kinetics in 1-D isothermal transformations and the linear growth kinetics in the 1-D continuous cooling case. During the 2-D peritectic reaction, where liquid, δ and γ phase are in mutual contact, the moving directions of interface are in accord with the driving force of the phase transformation at the interfaces.