Based on a three-dimensional modulated free carrier absorption （MFCA） model，simulation was performed to investigate the dependences of MFCA amplitude and phase on the electronic transport properties （the carrier lifetime，the carrier diffusivity，and the front surface recombination velocity） of semiconductor wafers at different pump-to-probe separations and different modulation frequencies. Experiments were performed with a silicon wafer，in which amplitude and phase were recorded as functions of modulation frequencies at several different two-beam separations. The electronic transport properties of semiconductor wafers were determined simultaneously via multi-parameter fitting procedure. These results showed that the method is capable of improving the measurement precision of the simultaneous multi-parameter determination of transport properties.