Solid　acids　usually　show　lower　catalytic　activities　than　liquid　acids　because　of　their　limited　acid　strength　and　presence　of　obvious　diffusion　limitation　in　the　reactions.　We　report　herein　a　variety　of　ionic　liquid-grafted　UiO-66　solid　superacids　synthesized　from　quaternization　of　UiO-66　with　1,3-propane　sultone,　ion-exchanging　with　H2SO4　or　HSO3CF3.　The　developed　UiO-66　solid　superacids　are　highly　efficient　in　catalyzing　biodiesel　production　toward　transesterification,　which　were　better　than　the　ionic　liquid　and　neat　H2SO4.　The　remarkable　activities　found　in　the　UiO-66　solid　superacids　benefit　from　the　synergistic　effect　of　high　acid　concentrations　(similar　to　3.33　mmol/g),　superacidity　(determined　by　P-31　solid-state　NMR,　Hammett　indicators,　and　potentiometric　titration),　as　well　as　unique　shape-selective　confinement　for　methanol　into　the　ordered　and　uniform　micropores,　which　targeted　the　activation　of　methanol　to　prevent　the　occurring　of　an　inverse　reaction　in　the　reactions.　The　UiO-66　solid　superacids　show　important　application　potentials　in　the　area　of　biodiesel　production　in　the　industry.