Why your car turn off when you stop the car?

some times a car turns it self off for a safety reasons if your on a hill and needing to close the fuel supply and sometimes its so fuel economy is increased...

Your car may shut off when you come to a stop for many different reason , none of which are stated above.

The idle control could be bad, the fuel filter may be bad, the fuel pressure regulator may be bad. You should really take the car to a mechanic.