Abstract: Bit freezing is a constant accident in drilling.With the price of down-hole tool getting higher and higher,the loss of stickiness is becoming bigger.A totally new back off technology developed in field practice was introduced here.It was to trip in flush casing first and clean the annular in the process.When the casing came to baker shoe,pump was put on and ?244.48 mm casing was run in after circulating clean out for a long time.Then the way of tripping a little in casing by drawing several times was adopted to release the freezing.By this way,the down hole logging instruments which worth of ten millions Yuan was saved as well as providing a new stuck freeing idea and method.