The invention discloses rhodobacter sphaeroides and a fermentation hydrogen generation method and application thereof. The preservation number of the rhodobacter sphaeroides is CGMCC No.18237. The rhodobacter sphaeroides is inoculated into a hydrogen generation culture solution, and illumination culture is conducted in an illumination culture box for hydrogen generation until hydrogen generation is finished. The strain can utilize carbon sources and nitrogen sources which are common in nature and are hardly utilized by most microorganisms for fermentation hydrogen generation, the hydrogen yield is significantly increased, and single-cell protein capable of being regarded as feed is produced while fermentation hydrogen generation is conducted. The rhodobacter sphaeroides is a variant of multifunctional rhodobacter sphaeroides and has a wide application prospect.