A millimeter wave security inspection instrument debugging system and a millimeter wave security inspection instrument debugging method, which are used for debugging the imaging definition of a millimeter wave holographic imaging security inspection system. A main control apparatus (100) is used for generating a millimeter wave detection signal and a reference signal. The main control apparatus (100) is also used for, where a millimeter wave transmitting antenna (300), a millimeter wave receiving antenna (400) and a detected object (500) are respectively located at different relative positions, transmitting the millimeter wave detection signal to the detected object (500) by means of the millimeter wave transmitting antenna (300), and receiving an echo signal reflected from the detected object (500) by means of the millimeter wave receiving antenna (400), and then using a holographic image technique to perform three-dimensional imaging according to the reference signal and the echo signal. The main control apparatus (100) can finally obtain a plurality of three-dimensional imaging results, so that the optimal relative positions of the millimeter wave transmitting antenna (300), the millimeter wave receiving antenna (400) and the detected object (500) can be determined, which results are applied to a millimeter wave holographic imaging security inspection system, thereby improving the imaging definition of the millimeter wave holographic imaging security inspection system.