The side bar go to the bottom of the content

hi support,

my blog is call https://www.iphall.com. The side bar should located on the side. But when I add more than 1 content. The sidebar will go to the bottom.
I have try to re install the wordpress. But the problem still happen.

I also try to go to the admin and set 1 content display. The sidebar is ok. But I want to display all the content according to the date. So when I put more than 2 to display the sidebar is always go to the bottom. Why? and how to treat this problem