hi, my HC-SR04 ultrasonic module is not working. when I connect Gnd and +5 , arduino uno switch off... what can I do for this? please help me....!!!! 
How do you know it isn't working?
You mention 3 connections- Power, Ground, and one Arduino pin.
The sensor you link to has 4 connections- Power, Ground, Trigger, and Echo.
I would start there.
Try this:
// Per.
when I connect Gnd and +5 , the arduino get short circuited.
and HC SR04 get high heated...
Either you reversed the +5V and GND at some point, or the module is just broken from the factory.
Desolder the two transducers (the metal cans) and maybe the xtal - they can come in handy later, discard of the rest, there is no way to repair it. Just order a new one (they are only a dollar apiece on eBay)
// Per.
hmmm okay... thank you then...