Nanoscale　tungsten　oxide,　as　a　functional　semiconductor　with　unique　physical　and　chemical　properties,　is　widely　used　in　environment,　energy,　life　science　and　information　technology　fields.　Based　on　the　application　of　first-principles　study　in　nanoscale　tungsten　oxide,　the　functions　of　theory　calculations　are　reviewed　in　the　paper.　Firstly,　the　development　and　basic　theory　of　the　first　principles　and　density　functional　theory　are　illustrated　based　on　quantum　mechanics.　Then,　the　commonly　related　software　in　such　field　of　semiconductors,　such　as　MS　(Materials　Studio)　and　VASP　(Vienna　ab　initio　Simulation　Package)　are　introduced.　Furthermore,　the　recent　study　of　the　first-principles　on　tungsten　oxide　in　terms　of　electronic　structure,　interaction　of　materials,　molecular　thermodynamics,　and　so　on,　is　clarified.　Finally,　the　existing　problems　and　future　developments　of　theory　calculations　used　in　the　field　are　summarized　and　prospected.