In　this　study,　a　multivariate　local　quadratic　polynomial　regression　(MLQPR)　method　is　proposed　to　design　a　model　for　the　sludge　volume　index　(SVI).　In　MLQPR,　a　quadratic　polynomial　regression　function　is　established　to　describe　the　relationship　between　SVI　and　the　relative　variables,　and　the　important　terms　of　the　quadratic　polynomial　regression　function　are　determined　by　the　significant　test　of　the　corresponding　coefficients.　Moreover,　a　local　estimation　method　is　introduced　to　adjust　the　weights　of　the　quadratic　polynomial　regression　function　to　improve　the　model　accuracy.　Finally,　the　proposed　method　is　applied　to　predict　the　SVI　values　in　a　real　wastewater　treatment　process　(WWTP).　The　experimental　results　demonstrate　that　the　proposed　MLQPR　method　has　faster　testing　speed　and　more　accurate　results　than　some　existing　methods.　(C)　2017　The　Chemical　Industry　and　Engineering　Society　of　China,　and　Chemical　Industry　Press.　All　rights　reserved.