The　preparation　of　high-quality　hydrogenated　amorphous　silicon　(a-Si:H)　film　with　a　new　microwave　electron　cyclotron　resonance-chemical　vapour　deposition　(MWECR-CVD)　system　assisted　with　hot　wire　is　presented.　In　this　system　the　hot　wire　plays　an　important　role　in　perfecting　the　microstructure　as　well　as　improving　the　stability　and　the　optoelectronic　properties　of　the　a-Si:H　film.　The　experimental　results　indicate　that　in　the　microstructure　of　the　a-Si:H　film,　the　concentration　of　dihydride　is　decreased　and　a　trace　of　microcrystalline　occurs,　which　is　useful　to　improve　its　stability,　and　that　in　the　optoelectronic　properties　of　the　a-Si:H　film,　the　deposition　rate　reaches　above　2.0　nm/s　and　the　photosensitivity　increases　up　to　4.71x10(5).