Handheld vacuum cleaner

A handheld vacuum cleaner, comprising:

• a dust cup assembly comprising:
• a cup casing arranged vertically;
• an airflow generation device;
• and
• a cyclone separation device, wherein the airflow generation device and the cyclone separation device being arranged in the cup casing, the airflow generation device being arranged above the cyclone separation device and located at a downstream side of the cyclone separation device, and an air vent being formed in a top of the cup casing;
• a suction nozzle assembly mounted to the cup casing and defining a suction channel;
• and
• a handle assembly mounted to the cup casing and used to be held;
• wherein an inner side of the air vent is provided with an air guide surface to adjust a blowing direction of the air vent, and an included angle a between an extension line of the air guide surface and a connection line between a central point of the air vent and a central point of a dust cup is projected onto a horizontal plane and satisfies:
• 10°≤α≤90°;
• wherein projected onto the horizontal plane, a width D between a front side wall of the air vent and a rear side wall of the air vent is larger than a width d between a rear side wall of an outer edge of the air guide surface and the rear side wall of the air vent, wherein the width d satisfies:
• 2 mm≤d≤6 mm.