Import csv file with multiple images in magento

First make a copy of

app/code/core/Mage/Catalog/Model/Convert/Adapter/Product.php 

  into 

app/code/local/Mage/Catalog/Model/Convert/Adapter/

Edit 

app/code/local/Mage/Catalog/Model/Convert/Adapter/Product.php 

and add the following code after line 778:

if (isset($importData['media_gallery']) && !empty($importData['media_gallery'])) {

        $x = explode(',', $importData['media_gallery']);

        foreach ($x as $file) {

            $imagesToAdd[] = array('file' => trim($file));

        }

        $mediaGalleryBackendModel->addImagesWithDifferentMediaAttributes(

            $product,

            $imagesToAdd, Mage::getBaseDir('media') . DS . 'import',

            false,

            false

        );

    }

Now file look like following: 

773        $addedFilesCorrespondence = $mediaGalleryBackendModel->addImagesWithDifferentMediaAttributes(
774            $product,
775            $arrayToMassAdd, Mage::getBaseDir('media') . DS . 'import',
776            false,
777            false
778        );


779    if (isset($importData['media_gallery']) && !empty($importData['media_gallery'])) {


780    $x = explode(',', $importData['media_gallery']);

781       foreach ($x as $file) {
782            $imagesToAdd[] = array('file' => trim($file));
783        }
784        $mediaGalleryBackendModel->addImagesWithDifferentMediaAttributes(
785            $product,
786            $imagesToAdd, Mage::getBaseDir('media') . DS . 'import',
787            false,
788            false
789        );
790    }




Now add a column *media_gallery* in your  CSV file, and put your other images in /media/import also. 

Add images as following:


media_gallery

-------------


/second_image.png, /third_image.png, /fourth_image.png