This study investigates the expression and significance of urinary protein and coagulation‐fibrinolysis indicators in preeclampsia, categorized into mild preeclampsia (109 cases) and severe preeclampsia (97 cases) based on disease severity. Additionally, 110 patients with gestational hypertension (gestational hypertension group) were included for comparative analysis. General information, laboratory indicators, urinary protein, and coagulation‐fibrinolysis indicator levels were collected for each group. Significant differences were observed in blood pressure among groups (P < .05), while uric acid, serum creatinine, aspartate transaminase, alanine transaminase, and triglycerides showed no significant differences (P > .05). Total cholesterol, triglycerides, and low‐density Lipoprotein levels in severe preeclampsia were higher than those in mild preeclampsia and gestational hypertension groups, whereas high‐density lipoprotein, albumin, and platelet levels were lower in severe preeclampsia. No significant differences were observed in prothrombin time or D‐dimer levels among groups (P > .05). Urinary protein, urinary protein quantification, activated partial thromboplastin time, thrombin time, and fibrinogen were identified as influencing factors for adverse maternal and infant outcomes in severe preeclampsia patients. The study concludes that urinary protein and coagulation‐fibrinolysis indicators are elevated in preeclampsia, particularly in severe preeclampsia cases, suggesting their potential use as diagnostic influencing factors for severe preeclampsia.