Fecha de publicación: -- Fuente: WIPO "tomato" The present invention relates to a mancozeb nanosuspension having a particle size less than 100 nanometers and a preparation method thereof. The mancozeb nano-suspension having a particle size less than 100 nanometers is formed by diluting and mixing two or three components with water. The preparation method is: under a condition that the stirring speed is not less than an effective stirring speed, adding a component one dilution to a component two dilution, or adding the component two dilution to the component one dilution to form the mancozeb nano-suspension.