A pile loom including a pile tension roller (5) supported displaceably with respect to a loom frame and a position detecting device that detects the front-rear-direction position of the pile tension roller performs tension control of a pile warp to adjust a let-off speed of a pile warp beam (2) based on a detection result of the position detecting device to cause the position of the pile tension roller to be within an allowable range to thereby cause the tension of the pile warp to be within a desired range. An abnormality determination position for determining an occurrence of a pile-height abnormality, in which pile slip-off successively occurs in pile fabrics during weaving, is previously determined. When the pile-height abnormality is detected based on the pile tension roller arriving at the abnormality determination position during operation of the loom, an abnormality signal is generated.