Abstract: Array monitor is an important self-monitor method of digital array antenna while antenna testing or radar normal working. Array monitor can find the abnormal channels in digital array antenna, and avoid the effects to antenna. Firstly, the principles and assortments of digital array antenna monitor are introduced, and the application scenarios of each monitor method are analysed. Secondly, several common channel abnormal types are described and the monitor methods and determinants of these types detailedly are introduced. Finally, are described the array monitor results with the real channel properties in actual array test are compared. The result verifies the availabilities of these array monitor methods. The beam forming result comparison of before and after array monitor provides the effort of monitor methods to digital array antenna.