Which countries’ visas will be affected by having an Iranian visa in your passport?

Generally there will be no impact

But you can consider washing your old passport and going to the State Administration of Foreign Exchange to apply for a new one before going to Europe or the United States. But if you really I have concerns, but I have an idea. After returning from abroad, I soak the passport in water until it is no longer usable, and then go to the Public Security Bureau to replace it. This is a legal reason, and it only costs 220 yuan.