Abstract: Photospheric magnetic field measurements and coronal polarized brightness observations are used as constrains to develop a single-fluid solar wind background model, which includes proton density, bulk velocity and magnetic field. Proton temperature will be dealed with in further studies, The synoptic maps of K-corona polarized Brightness （pB） at 1.36 solar radii observed by MKIII in High Altitude Observator （HAO） are applied to derive corona density according to the solar wind density model constructed by Guhathakurta in 1996. In order to determine the global magnetic field, the synoptic maps of photospheric magnetic field in Wilcox Solar Observatory （WSO） are adopted to be the bottom boundary condition of the model of horizontal current and current sheet （HCCS） established by Zhao in 1994. Researches on observations during Ulysses＇ first and second polar flybyes made by Phillips in 1995 and McComas in 2003 demonstrate that the solar wind momentum flux density scaled to 1 AU is almost invariant except that it is slightly small in the latitude of ±10°-30°, thus the solar wind speed can be derived from this conclusion and the obtained density data. The model is applied to study the solar wind background in Carrington Rotation （CR） 1918 and the results are roughly consistent with the observations in solar minimum. However, the area of high density and slow speed is slightly larger than that observed and thus the density model needs to be further improved.