A nasal aspirator,: the nasal aspirator comprises a casing , a lower suction nozzle , an upper suction nozzle , a liquid storage cup and an air pump unit ; the lower suction nozzle is disposed on an upper end of the casing , the lower suction nozzle has a chamber and a suction passageway therein, the chamber has an opening facing upward, an upper end of the suction passageway communicates with the chamber ; the upper suction nozzle is mounted to an upper end of the lower suction nozzle , the upper suction nozzle includes a main body shell , an inner tube and an outer tube , a lower end of the main body shell is hermetically connected to the upper end of the lower suction nozzle , the main body shell has a cavity with an opening facing downward, the cavity communicates with the chamber , the inner tube extends from a top wall of the cavity , the inner tube has a first passageway , the outer tube extends upward from an upper end face of the main body shell , the outer tube has a second passageway , the second passageway communicates with the first passageway ; the liquid storage cup is placed in the chamber and the cavity , the liquid storage cup includes a cup body and a cup cover , the cup body has an accommodating chamber with an opening facing upward, the cup cover is disposed on the cup body to cover the opening of the accommodating chamber , the cup cover is formed with a mounting hole , the inner tube passes through the mounting hole and extends into the accommodating chamber ; the air pump unit is disposed in the casing , an air intake end of the air pump unit communicates with a lower end of the suction passageway , the air pump unit has a motor , wherein the lower suction nozzle has a first boss extending from a bottom of the chamber , and the lower suction nozzle further has a connecting tube extending downward from a bottom of the lower suction nozzle , and the suction passageway is formed in the first boss and the connecting tube , characterized in that the cup cover is formed with a through hole , the through hole communicates with the accommodating chamber and the cavity , an outer wall of the inner tube is hermetically mated with an inner wall of the mounting hole ; the nasal aspirator comprises a control board , the control board is disposed in the casing ; a detection system for detecting a liquid is provided in the chamber , the detection system is connected to the control board , and the motor is connected to the control board ; and the cup cover is coupled to the cup body , a positioning post extends upward from an upper end of the cup body , the cup cover has a positioning hole , and the positioning post is inserted through the positioning hole and extends out of the cup cover . the air pump unit is disposed in the casing , an air intake end of the air pump unit communicates with a lower end of the suction passageway , the air pump unit has a motor , wherein the lower suction nozzle has a first boss extending from a bottom of the chamber , and the lower suction nozzle further has a connecting tube extending downward from a bottom of the lower suction nozzle , and the suction passageway is formed in the first boss and the connecting tube , characterized in that the cup cover is formed with a through hole , the through hole communicates with the accommodating chamber and the cavity , an outer wall of the inner tube is hermetically mated with an inner wall of the mounting hole ; the nasal aspirator comprises a control board , the control board is disposed in the casing ; a detection system for detecting a liquid is provided in the chamber , the detection system is connected to the control board , and the motor is connected to the control board ; and the cup cover is coupled to the cup body , a positioning post extends upward from an upper end of the cup body , the cup cover has a positioning hole , and the positioning post is inserted through the positioning hole and extends out of the cup cover . <EOS>