I'm working on a virtuemart page, but I faced with a problem, if the customer buy more than 50EURO than it is say that it is a free shipping, but I want to show the shipping method, with 0 shipping cost.
You can't change the way that works without a core hack. What you will need to do is make a new shipping module that calculates the order total and adjusts the shipping cost when the order total is high enough. You can probably make a copy of the shipping module you are using and add a little code to make it work.