Disclosed is a method for estimating tension of a chain of a scraper conveyor, belonging to a method for estimating chain tension. The method comprises the following steps: embedding strain sensors in a plurality of scrapers of a scraper conveyor to measure the tension of weak coupling points between the scrapers and chains, converting acquired sensor signals into data signals through an A/D conversion unit, transmitting the data signals to a data control center using a wireless transmission module, further processing the tension data information of the weak coupling points through the data control center, establishing a chain tension distribution model, and determining an the estimated tension of the chain of the scraper conveyor. The method provided by the present invention is simple, efficient and practical, and the estimation of tension of the whole continuous moving chain is completed by the tension measurement at limited positions of the chain. The chain of the scraper conveyor is meshed with a sprocket and continuously moves in a middle trough and its tension also changes in real time along with the load; the strain sensors are arranged on the scrapers to measure the tension of the weak coupling points between the scrapers and the chains, and the estimation of tension of the whole chain is completed by tension measurement at limited positions on the chain.