交流效果比较差怎么说英语

If you want to say that the communication is not going well, you can say:

"The communication isn't very effective."
"We're not really understanding each other."
"We seem to be having a lot of misunderstandings."
"We're not making much progress in our discussion."

You can also describe the specific problems you are having:

"We're not on the same page."
"We keep talking past each other."
"I'm having trouble understanding what you're trying to say."

It might also be helpful to suggest ways to improve the communication:

"Can we try to be more clear in our explanations?"
"Maybe it would help if we took a break and came back to this later?"
"Could we try to summarize what we've discussed so far to make sure we're both on the same page?"