Abstract: There was a sensitivity inconsistence phenomenon occurring on the right and left working position of magnetic particle testing machine CJW-3000. Following a careful checking, it was found that the inconsistence was caused by the screw steel plate oxide due to the suspension on the side of the conductive circuit, thus the corresponding resistance was increased. In order to improve the sensitivity and reliability, four resolution methods were put forward such as maintaining the equipment carefully, observing the magnetizing specification carefully, setting the alarm circuit of magnetizing time and setting sensitivity detection gauge.