To provide an control system for a yarn texturing machine, capable of detecting various kinds of abnormalities of the yarn online.

In this operation control system for a yarn processing machine, capable of controlling an operation state of a yarn processing machine online, the operation control system for a yarn processing machine is equipped with a data collection part for measuring the shape of a finished yarn, subjecting the measured signal to an A/D conversion into measured data of digital value at a fixed sampling period, successively memorizing the measured data at a fixed period and at a point of time when the latest value of measured data is out of a preset control range, memorizing measured data of a fixed period from the point of time besides the measured data memorized at the fixed period of time and with an abnormality treatment part for obtaining an average value of the whole memorized data and detecting an abnormality from the average value.