Abstract: BeiDou is developed by China independently, the distribution and number of its reflection events have special advantages, which is the important indicator of LEO-R(low earth orbit-reflection)constellation. By using the Walker architecture which has the advantage of the uniformity and stability to design LEO-R constellation, it can realize the global ocean remote sensing based on BeiDou reflected signals. The geometric relation between the constellation and BeiDou is analyzed and the judgment condition of the reflection events is also derived. The impacts of constellation parameters on the number and distribution of the BeiDou reflection events are quantitatively analyzed by proposing mark-traverse algorithm, at the same time, the chosed simulation scene is 36 hours Nepartak typhoon. The results show that the percentage of constellation coverage time is 97.619 73% and the maximum revisit time is 404.511 s, which validates the constellation good performance on the global remote sensing.