The　selection　of　timescale　algorithm　will　have　a　great　influence　on　the　accuracy　and　stability　of　timescale.　To　improve　the　accuracy　and　stability　of　timescale,　this　paper　studied　the　stochastic　model　of　the　hydrogen　clock　and　Hadamard　deviation　for　researching　the　Kalman　timescale　algorithm　based　on　the　hydrogen　clock　ensemble,　which　is　quite　different　from　the　traditional　Kalman　timescale　algorithm　based　on　the　model　of　cesium-beam　clock　ensemble,　mixed　ensemble　and　Allen　deviation.　The　Hadamard　variance　is　used　to　describe　the　stability　of　clock　frequency　in　this　paper;　it　will　improve　the　precision　of　the　Hydrogen　Clock　Ensemble.　By　using　Hadamard　variance　instead　of　Allen　avariance,　it　can　overcome　the　influence　of　frequency　drift.　In　this　paper,　the　clock　whose　stability　is　best　is　chosen　as　the　reference　clock　so　that　the　accuracy　and　stability　of　the　hydrogen　clock　ensemble　will　be　improved.　The　experiment　data　of　the　hydrogen　clock　ensemble　in　the　timekeeping　laboratory　of　National　Institute　of　Metrology　(NIM)　in　China　were　processed;　the　frequency　stability　can　be　improved　to　10＇15.　The　results　verified　that　the　Kalman　timescale　algorithm　based　on　the　hydrogen　clock　ensemble　is　effective.　©　2017　IEEE.