To make a post consisting photos that will dealing with the topic of 2018 FIFA World Cup.
To make a post consisting of photos related to [the topic of] the 2018 FIFA World Cup.*
What language are you translating from? There are a bit more words than necessary. The bracketed text above seems redundant (to me) but can be left in the sentence and I don’t think it would be incorrect.
Thanks for the contest! :)