I'm using iPhone smart case but the charging is continuous

it is not good for the iphone battery health, you are harming your battery by charging it 24/7. take it off before you damage your battery. only put it on if you need extra battery but once 90 percent take it off.

amrit52 wrote:

My question is i”m using iphone smart case but the charging is continuously this is good for the battery life of the phone in future.

No, it will not hurt your phone. The charging circuitry built into the phone will stop charing the battery once it reaches 100%.

See this article for more information:

When to charge your iPhone or iPad - Apple Community

You don't need to take it off. Leaving it on will NOT hurt your battery.