In　frequency-sweep　polarization-modulation　ranging,　distance　is　determined　by　the　frequency　of　modulated　waves　and　the　corresponding　wavelength　multiple　when　emitted　and　returned　waves　are　in　phase.　However,　measurement　of　the　frequency　and　the　wavelength　multiple　is　affected　by　thermally　induced　phase　delay　of　the　polarized　wave.　In　this　article　we　systematically　discuss　the　principle　of　the　ranging　method　and　analyze　the　influences　of　thermally　induced　phase　delay.　New　approaches　to　measurement　are　proposed　to　eliminate　the　impact　on　frequency　and　the　wavelength　multiple.　Theoretical　analysis　and　experimental　results　proved　the　efficiency　and　applicability　of　the　methods.