The invention discloses a broken chain detection device for a scraper conveyer. The broken chain detection device comprises a head frame, a transition tank, an intermediate tank, a plurality of scrapers with equal intervals, a chain, an infrared photoresistor device, an infrared light emitting light, a current sensor and a CPU processor, wherein an input end of the current sensor is connected to an infrared photoresistor in series to form a circuit and an output end is connected with the CPU processor; the CPU processor comprises a signal identification unit, a first judgment unit, a timing unit and a second judgment unit; the first judgment unit compares whether a time difference that the same scraper passes through the infrared photoresistor is shorter than a preset time value or not; and the second judgment unit compares whether the duration, that any two adjacent plates pass through the infrared photoresistor, recorded by the timing unit exceeds a mean value of the infrared photoresistor or not. Through the arrangement, broken chain detection of the chain is carried out from two aspects, so that the reliability of broken chain detection of the chain is further improved.