as you see in picture, the position of picture is not right. how can set position of picture to middle of page?
Change the layout settings to any of the "with text wrapping" presets, this should allow you to freely move the picture and center it. https://support.office.com/en-us/article/Wrap-text-around-a-picture-ad1bc334-0211-4619-9089-b0d657ed7e06#__toc286056724 for the official support page.
Position a picture
In your Word document, click the image to select it.
Click the contextual tools tab.
For example, if you select a photograph, click the Picture Tools tab.
If you select an AutoShape, click the Drawing Tools tab. If you select a SmartArt chart, click the SmartArt Tools Format tab.
In the Arrange group, click Position.
Under With Text Wrapping, click the location where you want to position the image.
NOTE If you click the In Line with Text option, your image stays with the text that comes before and after it.