If your Facebook Pixel Page View action is firing twice, it can happen for a few reasons.
Mostly it happens if you have some extra code in your page that is creating some weird behavior.
What you need to look into your page is for iframe or script tags. Mostly iframes, because that will create a page within a page, so basically, the page view Facebook pixel code will trigger twice.
If it still fires twice, look above the ending of the /head tag for any code that you think that might create this issue with the pixel code to fire twice.
Edit, remove whatever you can find and try again. The page view Facebook pixel code should only fire once now.
If you need more help, please leave in the comments.