Is there any gradle commnd to reimport new modules added into build.gradle ?

not really, because gradle isn't the IDE -- there is no "import", that's entirely handled by intellij. intellij should have a Gradle tab that you can hit a sync button on though

Sure, In Android-Studio I can find sync button appeared automatically but I cannot find any button after add new module into build.gradle in intelliJ IDE .

what does the Gradle tab look like? I don't think I've ever seen that tab without it

Where can I see the gradle tab ?

it's on the right hand side, assuming intellij thinks you have a gradle project loaded

Oh great !!!