Yarn dyeing machine

The utility model relates to a yarn dyeing machine which comprises a dyestuff injection system, a dyestuff circulating system, a yarn running system, a drying oven and a control module. The dyestuff injection system comprises a booster pump, a dyestuff storage box and an injection device. The dyestuff storage box is communicated with an inlet of the booster pump. An outlet of the booster pump is communicated with the injection device. The dyestuff circulating system comprises a dyestuff recycling box, a filter and a dyestuff pump. A dyestuff pipeline and the dyestuff recycling box are communicated with an inlet of the dyestuff pump. The filter is arranged between the dyestuff recycling box and the inlet of the dyestuff pump. An outlet of the dyestuff pump is communicated with the dyestuff storage box through the dyestuff pipe. The injection device corresponds to the dyestuff recycling box. By means of the yarn dyeing machine, the purpose of dyeing different colors on the same yarn is achieved by controlling the yarn running speed and dyestuff spraying time, and later spinning steps are simplified.