Adobe Photoshop is a graphic-editing suite that was developed by Adobe Systems. While Photoshop is an image creator and editing program, and not a page layout program like Adobe InDesign, and as such not really created to print across multiple pages, however, this can be achieved in a few ways, but it generally takes a bit more effort than in a program specifically created for this purpose.
Determine what the maximum size is that your printer can print. If you want to print a single, large image across multiple pages in Photoshop, you will need to know what the largest possible size is that your printer can output. This in turn will allow you to determine exactly how many pages you will need to print in order to complete the project. Your printer instruction manual or a quick look at the manufacturer's website will allow you to see exactly what the maximum print dimensions of your printer hardware is.
Determine what the size is of the image that you want to print across multiple pages. Once you know what the size of your completed project is, you can divide it by the size of your printer's maximum print size, in order to determine how many pages you will need.
Divide your final image into different sections that correspond to the maximum print size of your printer. This will allow you to print the pages individually and then take the resulting amount of pages and put them together to get the finished project. The easiest way to divide your picture into different sections is to use the Rectangular Marquee Selection tool and then use your mouse to drag out an area the same size as what your printed page will be.
Copy the first section by clicking on "Edit" and "Copy." Click on "File," and select "New." Photoshop will automatically change the dimensions of the canvas to fit the picture that was copied to the clipboard, so click "OK" in the pop-up menu without making any changes.
Repeat step 4 for the other sections, copying each section of the image onto its own page.
Print each individual page by clicking on "File" and selecting "Print". Make sure that the print resolution in the print dialogue box is of sufficient DPI (dots per inch) in order for the image to print clearly. For desktop printing, it should at least be 150 dpi. For professional printing, it needs to at least 300 dpi.
Check that the appropriate orientation is also selected in the page set-up within the print dialogue box. You will need to select either "landscape" (horizontal) or "portrait" (vertical) depending on how you want your image to print.
Assemble the printed pages into your final project. For a banner, attach the pages to each other in the correct sequence in order to get your overall final image.