The invention discloses a classification type environmentally friendly garbage bag which comprises an inner garbage bag made of waterproof cloth and an outer garbage bag connected with the inner garbage bag, wherein the bottom of the inner garbage bag is opened and provided with a bag bottom, and the opening is an outlet position of garbage and washing water; the top of peripheral cloth is provided with an elastic band having the characteristics of lengthening and contracting, which ensures that the shape of the garbage bag is suitable for being arranged on a round or square garbage can below a certain width, and moreover, the garbage can be tightly sleeved by the elastic band to prevent the garbage bag from falling in the garbage can; the port of the outer garbage bag on the peripheral cloth is provided with a bag port band button for controlling the bag port to enlarge and reduce so as to be convenient for the inlet of garbage and prevent the falling-off of the garbage; and the outer garbage bag on the peripheral cloth and the inner garbage bag form a garbage bag with multiple bags capable of classifying. The garbage bag can be used for classifying and cycling for a long time, is convenient to use and wash and achieves the purposes of reducing the use of disposable ordinary plastic garbage bags, reducing the environmental pollution and reducing the pressure of resource shortage.