HPW/BMMs　catalyst　was　prepared　by　supported　phosphotungstic　acid　on　bimodal　mesoporous　SiO2　via　impregation　method.　The　reusability　and　deactivation　of　HPW/BMMs　catalyst　during　the　esterification　of　waste　oil　with　methanol　were　emphatically　investigated.　The　structure　derivation　and　physico-chemical　properties　were　characterized　by　means　of　XRD,　FT-IR,　UV-Vis,　N2　adsorption-desorption,　31P　NMR　and　XRF.　The　results　showed　that　the　conversion　of　esterification　was　decreased　from　72.8%　to　60.1%　after　HPW/BMMs　catalyst　was　reused　4　times.　Meanwhile,　the　Keggin　structure　of　HPW　in　HPW/BMMs　catalysts　did　not　change　obviously,　but　the　structure　order　degree　of　BMMs　decreased　remarkably,　which　stemmed　from　the　influences　of　organic　molecules　on　the　mesoporous　surface　of　BMMs.　Furthermore,　both　the　coke　deposit　on　catalyst　surface　and　the　leaching　of　HPW　(from　36%　to　20%　after　4　times　recycle)　might　be　the　main　reasons　for　the　deactivation　of　HPW/BMMs　catalyst　during　waste　oil　esterification.