针对单从检测方向求解磁记忆信号梯度容易造成与检测方向同向的应力集中部位漏检的问题，应用多通道磁记忆检测仪检测了油田钻杆的应力及损伤状态，探讨了在对多通道磁记忆信号的切向分量求梯度时，从切向分量方向与法向分量方向进行联合梯度求解的方法。在钻杆的多通道磁记忆检测信号上进行了两种检测方法的对比，结果表明，从两个方向进行联合梯度求解的方法比只从检测方向求梯度效果更好。提出的方法对促进磁记忆检测技术用于钻杆检测，以及减少钻杆事故具有重要意义。

The stress and damage state of drill pipe in oilfield are detected by multi-channel magnetic memory tester. In order to overcome the disadvantage that gradient from single direction is easy to cause stress concentration region of the same direction as with the testing undetected, this paper proposed a method that combined the gradients of the testing direction and its vertical direction when one aimed to work out the gradient of the tangential component of multi-channel magnetic memory signal. It is proved that this method is better than gradient only from testing direction by the comparison of two methods in multi channel drill pipe magnetic memory testing signals. The method proposed in this paper is of great significance to promote the application of magnetic memory testing technology in the testing of drill pipe and reduce the accident of drill pipe.