Superfine denier high-strength polyester monofilament and preparation method thereof

The invention provides a superfine denier high-strength polyester monofilament and a preparation method thereof. The preparation method comprises the following steps that an inner cavity of a rotary drum of spinning equipment is subjected to vacuumizing treatment; the rotary drum is heated and filled with nitrogen to break a vacuum state; and slices are tackified in the rotary drum, the slices are heated, dried and subjected to solid phase polycondensation in a high-temperature vacuum state, the molecular weight of the slices is increased, low-molecular substances and water molecules are separated from slice main bodies, the viscosity of the tackified slices reaches 1.30-1.50, and the water content is smaller than or equal to 5 ppm. According to the method, a high-temperature vacuum environment is utilized, water molecules and low-molecular substances are removed in the slice tackifying process, and the stability of a melt in a slice molten state is guaranteed; meanwhile, a slow cooling area can guarantee the