[Vuejs]-How to implement dialog content destroy function after close vuetify dialog?

You can simply add a v-if to the v-dialog. This will get it removed completely from the DOM (destroyed) when closed.

<v-btn @click="showDialog = true">Show Dialog</v-btn>
<v-dialog v-if="showDialog" v-model="showDialog">
    <v-card>
        Hello World
    </v-card>
</v-dialog>