Welcome to the forum, and thanks for posting all of that information! Looking at your log file, I see a lot of these errors: WARNING no geometry in E:/lqshixi/InVEST/water_try1/分水岭1.shx FID: 89
I believe that the model should require that you enter the “.shp” file, not the “.shx” file for shapefiles. So first, try entering 分水岭1.shp for your watersheds. If you get the same error, then look closely at the watershed shapefile, since the model seems to think that there are no polygons in there. Let us know what you find.