protected $productCollectionFactory;
public function __construct(
        \Magento\Catalog\Model\ResourceModel\Product\CollectionFactory  $productCollectionFactory
){
     $this->productCollectionFactory = $productCollectionFactory;
}
function getAttributeProduct(){
$productcollection = $this->productCollectionFactory
    ->addAttributeToSelect('*')
    ->addAttributeToFilter('attribute code', 'option id');

$productcollection = $this->_productCollection
    ->addAttributeToSelect('*')
    ->addAttributeToFilter('age', 18)
    ->load();
}