Polytetrafluoroethylene (PTFE) -treated gas diffusion layer (GDL) can effectively improve water management in proton exchange membrane fuel cells (PEMFCs). Long-term operation of PEMFCs can cause PTFE shedding. Considering the random shedding of PTFE and the random distribution of liquid water, the motion behavior of liquid water in the GDL during purging is simulated using a multi-component multiphase lattice Boltzmann method (LBM). The effects of different PTFE shedding ratios, contact angles and initial water content are investigated. It is found that an increase in PTFE shedding ratio from 0 to 50% resulted in an increase in residual water content from 7.17% to 10.28%, despite the increase in porosity, which leads to a decrease in capillary force, and the viscous force of carbon fibers preventing water flow. At the same PTFE shedding rate, the larger the contact angle, the smaller the residual water content. The smallest residual water content is 6.47% at 20% initial water content, while the purging time increases 166.67% at 100% initial water content.