If you want to delete all product in magento than there is so many ways you can delete your product.

1st Way:- Delete all product in magento through admin

Go to admin >> Catalog >> Magnage Products >> and select Product and than select Delete in Action Drop down.(Please see image for more clarification)

2nd Way:-Delete all product using Mysql Query in a fastest way.
Please take a DB back Up before use it.

SET FOREIGN_KEY_CHECKS = 0;
TRUNCATE TABLE `catalog_product_bundle_option`;
TRUNCATE TABLE `catalog_product_bundle_option_value`;
TRUNCATE TABLE `catalog_product_bundle_selection`;
TRUNCATE TABLE `catalog_product_entity_datetime`;
TRUNCATE TABLE `catalog_product_entity_decimal`;
TRUNCATE TABLE `catalog_product_entity_gallery`;
TRUNCATE TABLE `catalog_product_entity_int`;
TRUNCATE TABLE `catalog_product_entity_media_gallery`;
TRUNCATE TABLE `catalog_product_entity_media_gallery_value`;
TRUNCATE TABLE `catalog_product_entity_text`;
TRUNCATE TABLE `catalog_product_entity_tier_price`;
TRUNCATE TABLE `catalog_product_entity_varchar`;
TRUNCATE TABLE `catalog_product_flat_1`;
TRUNCATE TABLE `catalog_product_link`;
TRUNCATE TABLE `catalog_product_link_attribute`;
TRUNCATE TABLE `catalog_product_link_attribute_decimal`;
TRUNCATE TABLE `catalog_product_link_attribute_int`;
TRUNCATE TABLE `catalog_product_link_attribute_varchar`;
TRUNCATE TABLE `catalog_product_link_type`;
TRUNCATE TABLE `catalog_product_option`;
TRUNCATE TABLE `catalog_product_option_price`;
TRUNCATE TABLE `catalog_product_option_title`;
TRUNCATE TABLE `catalog_product_option_type_price`;
TRUNCATE TABLE `catalog_product_option_type_title`;
TRUNCATE TABLE `catalog_product_option_type_value`;
TRUNCATE TABLE `catalog_product_super_attribute_label`;
TRUNCATE TABLE `catalog_product_super_attribute_pricing`;
TRUNCATE TABLE `catalog_product_super_attribute`;
TRUNCATE TABLE `catalog_product_super_link`;
TRUNCATE TABLE `catalog_product_enabled_index`;
TRUNCATE TABLE `catalog_product_website`;
TRUNCATE TABLE `catalog_product_relation`;
TRUNCATE TABLE `catalog_category_product_index`;
TRUNCATE TABLE `catalog_category_product`;
TRUNCATE TABLE `cataloginventory_stock_item`;
TRUNCATE TABLE `cataloginventory_stock_status`;
TRUNCATE TABLE `cataloginventory_stock_status_idx`;
TRUNCATE TABLE `cataloginventory_stock`;
TRUNCATE TABLE `core_url_rewrite`;
INSERT  INTO `catalog_product_link_type`(`link_type_id`,`code`) VALUES (1,'relation'),(2,'bundle'),(3,'super'),(4,'up_sell'),(5,'cross_sell');
INSERT  INTO `catalog_product_link_attribute`(`product_link_attribute_id`,`link_type_id`,`product_link_attribute_code`,`data_type`) VALUES (1,2,'qty','decimal'),(2,1,'position','int'),(3,4,'position','int'),(4,5,'position','int'),(6,1,'qty','decimal'),(7,3,'position','int'),(8,3,'qty','decimal');
INSERT  INTO `cataloginventory_stock`(`stock_id`,`stock_name`) VALUES (1,'Default');
TRUNCATE TABLE `catalog_product_entity`;
SET FOREIGN_KEY_CHECKS = 1;

3rd Way:- Delete all product through Script

<?php
require 'app/Mage.php';

$all_products = Mage::getModel('catalog/product')->getCollection();    
foreach ($all_products as $product) {
    try {
        $product->delete();
    } catch(Exception $e) {
        echo $e->getMessage();
    }
}

?>

4th Way:-

 By <strong>Sku, ProductId, Name</strong>
<?php
 
// Load the Magento product by entity_id
$product = Mage::getModel('catalog/product')->load($productId);

		OR 

// Load the Magento product by sku
$product = Mage::getModel('catalog/product')->loadByAttribute('sku', $productSku);
		
		OR
	
// Load the Magento product by name
$product = Mage::getModel('catalog/product')->loadByAttribute('name', $productName);
 
// Delete the product
$product->delete();

If you want to delete all category in magento Click Here

If you want to disassociated all products Images in magento Click Here

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