Abstract: The effects by the thread parameters and the field operation on thread galling performance are analyzed by means of getting the casing subjected to the make up/break out test under the simulation operation conditions.It is reveals via the studies that under the condition that all the other thread parameters remain unchanged,any slight change of the standoff of the male thread can significantly affect the anti-galling performance of the thread;the make up speed,choice of the back clamp and its holding position comprehensively have an important influence on the said anti-galling performance;and with the same clamping force,the clamping position for the make up operation should be as close as possible to the factory end,and the best clamping position should be kept with a distance as equal to 1/3 of the coupling length from the face of the factory end of the coupling.