The diaphragm is the main respiratory muscle, and its activity can be used to assess respiratory muscle function. Diaphragm function can be evaluated by its electrical activity (diaphragm electromyography, EMGdi) and mechanical functions such as pleural pressure reflected by esophageal pressure. Compared with esophageal pressure, EMGdi recorded by a multipair esophageal electrode catheter could serve as a more reliable biomarker of neural respiratory drive. The pathophysiological changes of various respiratory diseases including obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease are related to neural respiratory drive. Accurately recording EMGdi and quantifying neural respiratory drive has become an important tool for exploring disease pathogenesis and aiding in diagnosis. This article introduces the method for recording EMGdi and quantifying neural respiratory drive using a multipair esophageal electrode catheter, summarizing its value in the diagnosis and treatment of chronic respiratory diseases.