An injector failure cylinder diagnosis method based on signal deviation of an injector failure diagnosis system measures, by a controller, noise/vibration signals due to the combustion of an engine, separates an injector abnormal frequency band signal as an injector signal from the noise/vibration signals, divides cylinder number time series data, which use a signal maximum value of the noise/vibration signals as a cylinder #1, into segments, extracts a feature vector after confirming a segment number of the cylinder #1 with a vibration reduction signal of the noise/vibration signals re-measured using one of the cylinders as an idle cylinder and sorting it by injector causing vibration time series data, and confirms a failure injector with the feature vector, thereby independently diagnosing whether the injector for each cylinder is normal or abnormal considering the deviation of the noise/vibration signals between the injectors for each cylinder from the measured noise and vibration signals.