It　is　very　important　to　accurately　extract　the　instantaneous　frequency　(IF)　of　complex　non-stationary　signals,　so　the　signal　processing　methods　based　on　IF　are　widely　used　in　engineering.　However,　in　non-stationary　complex　vibration　signals,　it　is　difficult　to　extract　the　instantaneous　frequency　under　strong　noise　because　the　frequency　changes　rapidly.　This　paper　proposes　an　improved　multi-ridge　extraction　method　based　on　differential　synchro-squeezing　wavelet　transform　(DSWT).　First,　an　improved　method　DSWT　is　proposed　to　reduce　the　computation　time　and　image　noise　of　synchro-squeezing　wavelet　transform　(SWT).　The　running　time　of　the　algorithm　can　be　further　reduced　by　segmenting　the　signal　and　compressing　the　time-frequency　matrix.　The　image　noise　can　be　significantly　reduced　by　differentiating　SWT　time-frequency　matrix.　It　lays　a　good　foundation　for　the　extraction　of　the　time-frequency　ridge　line.　Secondly,　an　improved　multi-ridge　extraction　method　is　proposed.　The　ridge　jump　due　to　end　effect　can　be　eliminated　adaptively　in　segmented　extraction.　It　further　improves　the　time-frequency　aggregation　and　extraction　effect　of　the　wavelet　ridgeline　image.　Finally,　the　improved　multi-ridge　extraction　method　based　on　DSWT　(DSWT-IMRE)　is　verified　by　the　simulation　data　and　experimental　data　under　different　conditions.　Compared　with　the　method　proposed　in　previous　study,　the　results　show　that　DSWT-IMRE　has　higher　extraction　accuracy.