Objective To investigate the impact of florfenicol（FLO） exposure on decidualization and the role of mitochondria in this process. Methods Primary mouse decidual stromal cells（mDSCs）were used to establish a model of FLO exposure. After exposure to FLO（1.56，6.25，and 25.00 μg/mL），Phalloidin staining was used to observe cell morphology；Western blot was used to measure the expression of HOXA10，a maker molecule for decidualization； and investigate the influence of FLO on cell proliferation and apoptosis during decidualization；the fluorescent probe Mito-tracker Red was used to observe mitochondrial morphology； immunofluorescence assay was used to measure the expression of TOMM20，a marker protein for outer mitochondrial membrane，and the level of ATP to observe the influence of FLO on mitochondrial function in mDSCs. Results Exposure to 25.00 μg/mL FLO led to abnormal cell morphology，reduced the expression of the marker molecule for decidualization HOXA10（P=0.002），promoted apoptosis，and inhibited cell proliferation. Further analysis showed a reduction in the expression of marker protein for outer mitochondrial membrane TOMM20（P=0.010），abnormal mitochondrial morphology，and a reduction in the level of ATP（P=0.003）. Conclusion Exposure to 25.00 μg/mL FLO may disrupt the balance between the proliferation and apoptosis of mDSCs and damage the decidualization process，which is associated with mitochondrial function.