In this work, we propose a method using frequency modulated continuous waveform (FMCW) laser self-mixing interferometry (SMI) and all-phase fast Fourier transform (APFFT) for simultaneous measurement of speed and distance. APFFT offers superior accuracy in frequency determination by mitigating issues like the fence effect and spectrum leakage, contributing to high-accuracy measurement for speed and distance. Both simulations and experiments have demonstrated relative errors at the level of 10^-4 and 10^-3 for distance and speed measurements respectively. Furthermore, factors impacting measurement performance have been discussed. It provides a high-performance and cost-effective solution for distance and speed measurements, applicable across scientific research and various industrial domains.