Based　on　single-photon　noise　model　and　generalized　nonlinear　Schrodinger　equation　including　spontaneous　Raman　scattering　noise,　the　coherence　properties　of　supercontinuum　under　various　pulse　widths　of　the　pump　pulse　and　input　pulse　wavelength　are　theoretically　analyzed　from　the　coherence　and　phase　angle　evolution　of　spectra　in　the　frequency　domain.　The　results　show　that,　in　order　to　obtain　a　high　degree　of　coherence　supercontinuum　light　source　and　suppress　the　modulation　instability　to　noise　amplification,　the　soliton　fission　of　distance　must　be　smaller　than　the　modulation　instabilities　distance.　Using　shorter　pump　pulse,　the　pump　pulses　in　the　normal　dispersion　region　or　in　the　region　of　anomalous　dispersion　far　from　zero-dispersion　wavelength,　the　absolute　value　of　the　second-order　dispersion　coefficient　is　added　to　obtain　highly　coherent　supercontinuum.