一摞纸怎么说英语

A stack of paper can be referred to as a "pile of paper" in Engpsh. Here are a few other ways you could describe it:

A sheaf of paper
A bundle of paper
A ream of paper (typically 500 sheets)

For example: "Can you please pass me that pile of paper on the desk?" or "I need to print out 50 copies of this report, so I'll need at least two reams of paper."