Abstract: Multipath and gross errors are the most important factors of high-precision and high-reliability GPS baseline solution,especially for short period and low sampling rate.Two main kinds of traditional GPS baseline solution models are introduced,on the basis of which,a new GPS baseline solution model,utilizing single epoch methodology to obtain baseline solution,is proposed.It is thus solved by reducing multipath errors of coordinate series taking full advantage of low sampling rate of multipath errors and adopting wavelet multi-scale method to extract and eliminate the multipath error in prior to averaging the residual series to obtain the baseline solution.Meanwhile,the precision and reliability of baseline solutions are improved by remedying gross errors of epochs,based on dynamic coordinate and series residuals series.The results of tests confirm that multipath errors are eliminated to a great extent,utilizing the new model,especially for short period,and the precision and reliability of baseline solutions are enhanced by detecting and reducing gross errors on the basis of combination of coordinate series and residuals series.