A vacuum generator, comprising: a generator body provided with an air inlet, a contraction pipe section, an expansion pipe section, a negative pressure generation cavity, and an air outlet that are sequentially communicated, wherein in a ventilation direction from the air inlet to the air outlet, a pipe diameter of the contraction pipe section is gradually decreased, a pipe diameter of the expansion pipe section is gradually increased, and the negative pressure generation cavity is constructed to generate an inner cavity jet flow negative pressure when gas ejected from the expansion pipe section flows through the negative pressure generation cavity; wherein the generator body is characterized in that a negative pressure suction flow channel is provided, the negative pressure suction flow channel comprises a suction port section and a reduced-diameter flow channel section, one end of the reduced-diameter flow channel section communicates with the negative pressure generation cavity, and the other end communicates with one end of the suction port section, the other end of the suction port section penetrates through a side wall of the generator body, and in an air intake direction of the reduced-diameter flow channel section, a cross-sectional area of the flow channel of the reduced-diameter flow channel section is gradually decreased; wherein from one end of the negative pressure generation cavity communicating with the expansion pipe section to one end of the negative pressure generation cavity communicating with the air outlet, a cross-sectional area of the flow channel of the negative pressure generation cavity is gradually decreased; and wherein a cavity wall of the negative pressure generation cavity is a horn-shaped curved wall, and the horn-shaped curved wall is a curved structure enclosed by the motion trajectory of an arc-shaped generatrix when it moves around the central axis. a generator body provided with an air inlet, a contraction pipe section, an expansion pipe section, a negative pressure generation cavity, and an air outlet that are sequentially communicated, wherein in a ventilation direction from the air inlet to the air outlet, a pipe diameter of the contraction pipe section is gradually decreased, a pipe diameter of the expansion pipe section is gradually increased, and the negative pressure generation cavity is constructed to generate an inner cavity jet flow negative pressure when gas ejected from the expansion pipe section flows through the negative pressure generation cavity; wherein the generator body is characterized in that a negative pressure suction flow channel is provided, the negative pressure suction flow channel comprises a suction port section and a reduced-diameter flow channel section, one end of the reduced-diameter flow channel section communicates with the negative pressure generation cavity, and the other end communicates with one end of the suction port section, the other end of the suction port section penetrates through a side wall of the generator body, and in an air intake direction of the reduced-diameter flow channel section, a cross-sectional area of the flow channel of the reduced-diameter flow channel section is gradually decreased; wherein from one end of the negative pressure generation cavity communicating with the expansion pipe section to one end of the negative pressure generation cavity communicating with the air outlet, a cross-sectional area of the flow channel of the negative pressure generation cavity is gradually decreased; and wherein a cavity wall of the negative pressure generation cavity is a horn-shaped curved wall, and the horn-shaped curved wall is a curved structure enclosed by the motion trajectory of an arc-shaped generatrix when it moves around the central axis.