How to Delete all products programmatically in Magento

Please try below code,

$products = Mage::getResourceModel('catalog/product_collection')->getAllIds();
foreach ($products as $key => $productId)
{
    try {
        $product = Mage::getSingleton('catalog/product')->load($productId);
        Mage::dispatchEvent('catalog_controller_product_delete', array('product' => $product));
        $product->delete();
    } catch (Exception $e) {
        echo "<br />Cannot delete product ID: $productId";
        }
}