The invention discloses a cigarette processing quality evaluation and diagnosis method. The cigarette processing quality evaluation and diagnosis method includes drawing a contour map of sample probability by collecting and processing historical data, diagnosing the abnormal technological parameters or indexes by the contour map and computing the quality. By computing of the sample probability, diagnosis of the abnormal parameters or indexes and computing of the sample quality, more complete and practical quality evaluation references are provided for quality management personnel, and a fast channel is provided for quality improvement. The cigarette processing quality evaluation and diagnosis method can evaluate product quality and physical quality of cigarettes during cigarette tobacco production, and can further diagnoses and indicates the technological parameters or indexes deviated from the statistics controlled states when small-probability events (such as quality inconformity) appear. The cigarette processing quality evaluation and diagnosis method has the advantages of universality and applicability to other production processes besides the tobacco industry.