I want to make the system in the last page to be like the previous page 
Do you mean remove the extra space between systems so they are closer together?
If so, that’ll be Layout Options–Vertical Spacing–Vertical Justification. Set the percentage in the second bow to a higher value, like 90%.
The quickest way by far is to switch to Engrave mode, select the frames tool (the square icon in the left panel) then grab the bottom of the music frame and drag up.
This will create a page override, though, so it’s not necessarily the best method if you’re going to e.g. add or remove bars from this layout in future.
The systems on your last page are more widely spaced because there’s only 4 systems on that page, whereas on the previous page there are 5. You can either reduce the threshold for vertical justification to a level where Dorico doesn’t justify the last page - but this will probably end up with the staves more tightly spaced than the previous page, because the previous page is vertically justified.
Your other option is to select Frames in the Engrave mode toolbox, and move the bottom of the music frame on the last page upwards, until you’re happy with where the staves inside the frame are positioned. (If you want to re-use this page formatting, create a master page with the required music frame height so you can apply the same music frame size to multiple pages in multiple layouts.)