To　robustly　and　adaptively　reconstruct　displacement,　we　propose　the　amplitude　modulation　integral　reconstruction　method　(AM-IRM)　for　displacement　sensing　in　a　self-mixing　interferometry　(SMI)　system.　By　algebraically　multiplying　the　SMI　signal　with　a　high-frequency　sinusoidal　carrier,　the　frequency　spectrum　of　the　signal　is　shifted　to　that　of　the　carrier.　This　operation　overcomes　the　issue　of　frequency　blurring　in　low-frequency　signals　associated　with　continuous　wavelet　transform　(CWT),　enabling　the　precise　extraction　of　the　Doppler　frequency　of　the　SMI　signal.　Furthermore,　the　synchrosqueezing　wavelet　transform　(SSWT)　is　utilized　to　enhance　the　frequency　resolution　of　the　Doppler　signal.　Our　experimental　results　demonstrate　that　the　proposed　method　achieves　a　displacement　reconstruction　accuracy　of　21.1　nm　(0.89%).　Additionally,　our　simulations　demonstrated　that　this　method　can　accurately　reconstruct　target　displacement　under　the　conditions　of　time-varying　optical　feedback　intensity　or　a　signal-to-noise　ratio　(SNR)　of　0　dB,　with　a　maximum　root　mean　square　(RMS)　error　of　22.2　nm.　These　results　highlight　its　applicability　in　real-world　environments.　This　method　eliminates　the　need　to　manually　determine　the　window　length　for　time-frequency　conversion,　calculate　the　parameters　of　the　SMI　system,　or　add　additional　optical　devices,　making　it　easy　to　implement.