In　this　paper,　aiming　at　the　problems　existed　in　the　conventional　MWECR　CVD　system　using　to　prepare　silicon-substrate　thin　films,　such　as　lower　microwave　transform　power,　lower　plasma　density　and　higher　photodegradation　etc.,　the　system　was　improved　necessarily　and　efficiently,　in　which　we　focused　on　the　studies　for　the　microwave　coupling　structure,　magnetic　field　structure　and　deposition　system　structure.　The　experimental　results　showed　that　the　improved　microwave　coupling　structure　can　produce　high-microwave-transform　efficiency　of　about　90%,　the　improved　magnetic　field　structure　can　not　only　reduce　the　weight　and　volume　of　the　conventional　system　but　also　obtain　higher　magnetic　field　strength　which　was　two　times　that　of　the　single　coil　magnetic　field　and　useful　to　obtain　higher　plasma　density　on　the　sample　holder,　and　the　addition　of　the　hot　wire　system　can　make　the　photodegradation　decrease　remarkably.　In　the　result,　the　thin　films　prepared　by　using　this　improved　system　performed　excellent　properties,　such　as　high　photosensitivity　of　1.54　x　10(5),　high　deposition　rate　of　about　1　nm/s　and　low　photodegradation,　etc.　(C)　2008　Elsevier　B.V.　All　rights　reserved.