Objective. To probe into the relationship between pathological changes of the placenta and adverse pregnancy outcomes in pregnant women with preeclampsia. Methods. 67 pregnant women with preeclampsia admitted to our hospital between Jan. 2020 and Jan. 2021 were chosen as the experimental group, with 67 healthy pregnant women with normal prenatal examination during the same period as the control group, with their pregnancy outcomes recorded. After fetal delivery, the tissue of the central part of the maternal side of the placenta and the decidual tissue were taken and fixed in 10% formaldehyde solution. The expression of the inhibitor of apoptosis proteins (IAP) sur-vivin and the apoptosis promoting factor caspase-3 was determined by immunohistochemistry streptavidin peroxidase method; the pathological changes of placenta such as nodular hyperplasia of syncytiotrophoblast (ST), cytotrophoblast (CT), villous interstitial fibrosis, fibrinoid necrosis, and decreased villous vessels were observed by H&E staining; and the correlation between pathological changes of the placenta and adverse pregnancy outcomes was analyzed by r-analysis and regression analysis. Results. In the experimental group, fetal growth restriction, respiratory distress, neonatal asphyxia, and perinatal death occurred in 15 (22.39%), 32 (47.76%), 31 (46.27%), and 6 (8.96%) cases, respectively, with fetal birth weight (1243.49±453.20) g and placental weight (374.79±32.38) g. Sur-vivin was remarkably lower (P<0.001) and caspase-3 was remarkably higher (P<0.001) in the experimental group than in the control group. The experimental group had remarkably more nodular hyperplasia of ST, CT, villous interstitial fibrosis, fibrinoid necrosis, and decreased villous vessels than the control group (P<0.001). Sur-vivin showed negative correlation with fetal growth restriction, respiratory distress, neonatal asphyxia, and perinatal death (P<0.05), and caspase-3 showed positive correlation with fetal growth restriction, respiratory distress, and neonatal asphyxia (P<0.05). Binary logistic regression analysis confirmed that there was a correlation between nodular hyperplasia of ST, CT, villous interstitial fibrosis, fibrinoid necrosis, and decreased villous vessels with adverse pregnancy outcomes. Conclusion. There is a correlation between the pathological changes of the placenta and adverse pregnancy outcomes in pregnant women who have preeclampsia with nodular hyperplasia of ST, CT, villous interstitial fibrosis, fibrinoid necrosis, decreased villous vessels, decreased sur-vivin, and increased caspase-3. Therefore, in the future, it is expected that the pregnancy outcomes of patients with preeclampsia can be improved by interference in their expression of sur-vivin and caspase-3.