Microfibers (natural, regenerated and synthetic) have become a global pollution problem. The dyeing process in the textile industry is one of the main sources of microfiber pollution, while receiving limited attention. A printing and dyeing wastewater treatment plant in a textile industrial park in China was selected for this study. We systematically investigated the occurrence, release and removal characteristics of microfiber in wastewater treatment plants and assessed their contamination risk. Results showed that the microfiber concentration in the influent of printing and dyeing wastewater was 263.1 ± 46.7 MFs/L, in the effluent it was 55.5 ± 10.2 MFs/L, and in the RO effluent it was 8.9 ± 2.8 MFs/L. Although microfiber removal is not inefficient, wastewater treatment plants still release large quantities of microfiber every day. The FTIR results indicated that cellophane is the most common microfiber in this wastewater plant. This also provides a new direction for subsequent microfiber research. Finally, we evaluated the contamination risk of microfiber using various methods. Our study provides a reference for cleaner production in the textile printing and dyeing industry and a feasible direction for future research on microfiber pollution.