The invention relates to a multi-stage depressed collector of a strip-shaped electron beam traveling wave tube, and belongs to the technical field of vacuum electrons. The multi-stage depressed collector comprises multiple stages of gradually depressing electron collecting electrodes, wherein the main body collecting electrode comprises an electron beam channel, a transition cavity and an elliptical cavity which are connected in sequence; compared with the previous stage of electron collecting electrode, the section size of the electron beam channel of the next stage of electron collecting electrode is gradually increased while the eccentricity of the electron beam channel is gradually decreased, and the section size of the elliptical cavity is gradually increased while the eccentricity ofthe elliptical cavity is gradually decreased; and the tail stage of electron collecting electrode includes a metal baffle plate and a conical electrode, and the conical electrode extends into the elliptical cavity of the previous stage of electron collecting electrode. The multi-stage depressed collector is simple in structure and easy to process, can be used for well collecting the electron beams of strip-shaped electron beam traveling wave tubes after interaction and has high collecting efficiency and low electron reflux rate; the working efficiency of the whole strip-shaped electron beam traveling wave tube can be improved; and the electrons can be uniformly applied to the inner wall of each electrode, so that local overheating of the collector is prevented, and the requirement on a heat dissipation system is lowered.