The invention relates to an alignment layer detection machine used for detecting whether a groove on an alignment layer has defects or not. The alignment layer detection machine comprises a steam supplying mechanism and a sealing chamber. The steam supplying mechanism is used for inputting steam into the chamber; the chamber is used for accommodating a base plate for an alignment layer to be detected inside; at least part of the wall of the chamber is transparent. When the alignment layer detection machine detects whether the groove on the alignment layer has defects or not, the base plate is accommodated in the chamber, the water particle forming speed of the surfaces of the substrate and alignment layer is increased, the thicknesses of the water particles of the surfaces of the substrate and alignment layer are even, time for detection is shortened, and the detecting efficiency and the accuracy of detection results are improved; a machine vision detecting mechanism can be adopted for detection, and the detecting efficiency and reliability of the detection results can be further improved.