The InGaAs PIN photoelectric detector has great value in fields of spatial remote sensing and satellite communication .Evolvement rules of the output electrical signal noise are studied with the experiment of acceleration aging at constant temperature 358 K when the detector operates stablly in a long term. And on this basis,failure analysis of the detector working in long-term is discussed by comparison with the fore-and-aft linear region and temperature property of its noise. The theoretical results indicate that after operating stablly in about 10.8 years,thermal noise of the detector′s background noise will increase about 20%,and dark current noise about 0.35%. For the linear region of two detectors 13.31% and 9.95% are declined. Furthermore,the output noise model is modificated according to the analysis and the results of the experiments.