Please help me. my phantom 3 standard have this problem.  Please help I don't know what can I do

Faulty IMU unit? Or just need to keep trying to calibrate it perhaps? Maybe this can help? http://forum.dji.com/forum.php?mod=viewthread&tid=29724
The key is making sure it's on a level ground with no external force on it like wind or vibrations so best do it indoors.

Keep trying if it fails. If it continues to fail contact DJI tech team... gl

When she fly last, the weather was snowy and a bit of wind,  perhaps that was the reason

this happens after a crash and needs a good smack to un stick the gyro
watch in youtube and
read the comments on a possible fix

check for any loose connections of your cables.like the gyro located at the center.