The invention relates to an automatic detergent-adding washing machine and a washing method, in particular to a washing method which automatically adds detergent according to five factors, namely the weight, dirty degree, cloth characters of clothes, as well as the temperature and hardness of washing water. Due to the technical proposal, the invention provides the automatic detergent-adding method which automatically adds the most reasonable detergent on the premise of without affecting washing effects, prevents the circumstances that the detergent manually added is too little or excessive, saves resources, and reduces the pollution of discharged washing water on environment.