I download the app,and then build it。
But when the app runs on Iphone7 and Iphone6s, the app is very unfluency and the iphone become too hot
What do you mean by download app? Do you have a link to your project?
publish => download => ios dowload
http://119.29.222.114/COS/index.html
I don’t have an iPhone to test with but tried it on my Android Samsung S7 and it loads.
I recommend connecting it to Safari dev tools to see if there are any errors.