Classical　statistical　average　values　are　generally　generalized　to　average　values　of　quantum　mechanics.　It　is　discovered　that　quantum　mechanics　is　a　direct　generalization　of　classical　statistical　mechanics,　and　we　generally　deduce　both　a　new　general　continuous　eigenvalue　equation　and　a　general　discrete　eigenvalue　equation　in　quantum　mechanics,　and　discover　that　a　eigenvalue　of　quantum　mechanics　is　just　an　extreme　value　of　an　operator　in　possibility　distribution,　the　eigenvalue　f　is　just　classical　observable　quantity.　A　general　classical　statistical　uncertain　relation　is　further　given,　and　the　general　classical　statistical　uncertain　relation　is　generally　generalized　to　the　quantum　uncertainty　principle;　the　two　lost　conditions　in　classical　uncertain　relation　and　quantum　uncertainty　principle,　respectively,　are　found.　We　generally　expound　the　relations　among　the　uncertainty　principle,　singularity　and　condensed　matter　stability,　discover　that　the　quantum　uncertainty　principle　prevents　the　appearance　of　singularity　of　the　electromagnetic　potential　between　nucleus　and　electrons,　and　give　the　failure　conditions　of　the　quantum　uncertainty　principle.　Finally,　we　discover　that　the　classical　limit　of　quantum　mechanics　is　classical　statistical　mechanics,　the　classical　statistical　mechanics　may　further　be　degenerated　to　classical　mechanics　and　we　discover　that　merely　stating　that　the　classical　limit　of　quantum　mechanics　is　classical　mechanics　is　a　mistake.　As　application　examples,　we　deduce　both　the　Schrodinger　equation　and　the　state　superposition　principle,　and　deduce　that　there　exists　a　decoherent　factor　from　a　general　mathematical　representation　of　the　state　superposition　principle;　the　consistent　difficulty　between　statistical　interpretation　of　quantum　mechanics　and　determinant　property　of　classical　mechanics　is　overcome.