Abstract: To investigate how polyethylene (PE) microplastics of different sizes affect Chinese cabbage growth and nutrient uptake, three consecutive seasons of pot experiments were conducted. This study examined the impact of PE microplastics (<25, 25~48, 48~150, and 150~850 µm) on cabbage biomass, chlorophyll levels, nutrient content, and soil available nutrients. The research results indicate that PE microplastics significantly reduced cabbage biomass. Treatments with particles <150 µm decreased biomass by 10.14%~12.93% and 14.90%~19.90% in the first two seasons, respectively. All four particle size treatments significantly lowered chlorophyll b and total chlorophyll (a+b) across all seasons. Chlorophyll b decreased by 66.80%~86.70%, 43.18%~68.82%, and 44.76%~63.92%, while total chlorophyll decreased by 50.88%~70.42%, 18.86%~29.98%, and 33.22%~46.04%. PE also significantly reduced the content nutrient elements of cabbage. In the first two seasons, all treatments lowered cabbage Mn content by 35.14%~47.84% and 54.39%~69.15%. With persistent PE in the soil, DTPA~Mn dropped by 14.38%~29.71% in the last two seasons, and soil available P decreased by 19.35%~45.77% in the third season. PE application decreased cabbage starch content but significantly increased soluble sugar. Additionally, the smaller the particle size, the more significant the impact of PE microplastics on the above indicators. Our results suggest that PE inhibits nutrient absorption (e.g., Mn) in Chinese cabbage, likely through physical barrier effects. This limits photosynthetic pigment synthesis, reduces photosynthetic efficiency, and subsequently impairs starch synthesis, ultimately hindering growth. This inhibitory effect increases as PE particle size decreases and persists over multiple seasons.