In　this　study,　a　series　of　transition　metal-doped　TiO2　was　prepared　by　a　simple　sol-solvothermal　method.　Mix　an　ethanol　solution　of　tetrabutyl　titanate　and　metal　nitrate　solution　to　obtain　a　homogeneous　sol,　which　is　then　subjected　to　solvothermal　treatment.　After　calcination,　the　metal-TiO2　naoncomposite　was　obtained.　Selected　transition　metal　precursors,　including　Cu,　Fe,　Ag,　Cr,　Co　and　Zn,　were　doped　into　TiO2　nanocatalysts　to　assess　photocatalytic　degradation　activities.　The　results　show　that　1　mol　%　Ag-TiO2　photocatalyst　has　a　larger　specific　surface　area,　a　stable　anatase　phase　and　the　narrowest　forbidden　band　energy　(3.00　eV).　In　photocatalytic　degradation　of　methyl　orange　(MO)　tests,　1　mol　%　Ag-TiO2　could　reach　100　%　decolourisation　after　70　min　and　75.43　%　mineralisation　after　90　min.　ESR　analysis　confirmed　that　Ag　doping　significantly　increased　the　content　of　&　sdot;O-2(-)　and　&　sdot;OH　for　the　TiO2　catalyst,　which　are　responsible　for　the　oxidation　reactions　and　consequently　degradation　of　pollutants.　The　photocatalytic　degradation　mechanism　of　MO　was　also　proposed.　The　TOC　analyses　confirmed　the　mineralization　of　MO.　The　excellent　thermal　and　chemical　stability　of　1　mol　%　Ag-TiO2　has　also　been　demonstrated　by　thermogravimetric　analysis　and　cycling　experiments.　Electrochemical　tests　have　also　demonstrated　the　excellent　electrochemical　properties　of　1　mol　%　Ag-TiO2.