A prolonged-release pharmaceutical composition for oral administration, comprising: a) an immediate release component, comprising furazidin and one or more pharmaceutically acceptable excipients; and b) a modified-release component, comprising furazidin, a controlled-release agent, and one or more pharmaceutically acceptable excipients, wherein the pharmaceutical composition is a single dosage form in the form of a bilayer tablet, in which the immediate release component a) forms a first layer, the modified-release component b) forms a second layer, and the first layer at least partially covers the surface of the second layer, in a matrix of the modified-release component b), the controlled-release agent comprises at least one pH-independent polymer, which is at least one selected from the group consisting of hydroxypropylmethylcellulose (HMPC), hydroxyethylcellulose (HEC), hydroxypropylcellulose, xanthan gum, sodium carboxymethylcellulose, non-ionic poly(ethylene oxide), and any combination thereof, the immediate-release component has an in vitro dissolution rate of at least 80 wt.% of the furazidin within 45 minutes, based on the total furazidin content of the immediate release component, the modified-release component has an in vitro dissolution rate of 5 to 15 wt.% of furazidin within 2 h, based on the total furazidin content of the modified-release component, and the prolonged-release pharmaceutical composition has an in vitro dissolution rate of furazidin of 10 to 40 wt.% within 1 h, 40 to 65 wt.% within 6 h and above 80 wt.% within 14 h, based on the total furazidin content of the single dosage form, and the dissolution rates being determined by using European Pharmacopoeia edition 10 Apparatus Baskets "1" in 1000 ml volume of phosphate buffer solution of pH=6.8 with the addition of 2.5% CTAB (hexadecyltrimethylammonium bromide) at 37.0°C±0.5°C and 100 rpm. a) an immediate release component, comprising furazidin and one or more pharmaceutically acceptable excipients; and b) a modified-release component, comprising furazidin, a controlled-release agent, and one or more pharmaceutically acceptable excipients, the pharmaceutical composition is a single dosage form in the form of a bilayer tablet, in which the immediate release component a) forms a first layer, the modified-release component b) forms a second layer, and the first layer at least partially covers the surface of the second layer, in a matrix of the modified-release component b), the controlled-release agent comprises at least one pH-independent polymer, which is at least one selected from the group consisting of hydroxypropylmethylcellulose (HMPC), hydroxyethylcellulose (HEC), hydroxypropylcellulose, xanthan gum, sodium carboxymethylcellulose, non-ionic poly(ethylene oxide), and any combination thereof, the immediate-release component has an in vitro dissolution rate of at least 80 wt.% of the furazidin within 45 minutes, based on the total furazidin content of the immediate release component, the modified-release component has an in vitro dissolution rate of 5 to 15 wt.% of furazidin within 2 h, based on the total furazidin content of the modified-release component, and the prolonged-release pharmaceutical composition has an in vitro dissolution rate of furazidin of 10 to 40 wt.% within 1 h, 40 to 65 wt.% within 6 h and above 80 wt.% within 14 h, based on the total furazidin content of the single dosage form, and the dissolution rates being determined by using European Pharmacopoeia edition 10 Apparatus Baskets "1" in 1000 ml volume of phosphate buffer solution of pH=6.8 with the addition of 2.5% CTAB (hexadecyltrimethylammonium bromide) at 37.0°C±0.5°C and 100 rpm. <EOS>