you can use the CSV import feature (easiest to do this with microsoft excel spreadsheet version of the csv file).
zip up all your product images and upload them to your server via FTP to your hikashop uploads folder.
Then extract the zip file on the server so you get all your images in place.
Then in your product csv file , just put the image names in the excel spreadsheet image column with all the image names for a product separated by a comma (for example: product_1.jpg,product_2.jpg,product_3.jpg)
Then upload the spreadsheet(csv file) into hikashop and it will insert/update all your products with the images.
We have used this method to add hundreds of products and images into hikashop all at once. Import/Export feature of hikashop is one of our favorite features. Now if we could just get the FedEx shipping plugin to work, we would be loving life.