Objective To explore the clinical value of the combined application of modified fetal biophysical profile score (BPS), non-stress test (NST), and fetal blood flow spectrum detection in the diagnosis of intrauterine fetal distress.Methods A total of 157 singleton pregnant women who visited the hospital due to self-reported "decreased fetal movement" from January 2020 to December 2023 were selected as the research objects. All subjects underwent modified BPS, NST, and color Doppler ultrasound to detect the blood flow spectra of fetal umbilical artery (UA) and middle cerebral artery (MCA), including systolic/diastolic ratio (S/D), pulsatility index (PI), resistance index (RI), and the MCA-PI/UA-PI ratio was calculated. According to the diagnostic criterion of a 1-minute Apgar score ≤ 7, the enrolled neonates were divided into a fetal distress group (22 cases) and a non-fetal distress group (135 cases). The diagnostic efficacy of each index and combined detection was analyzed by receiver operating characteristic (ROC) curve.Results This study included 157 pregnant women, of whom 22 (14.01%) were diagnosed with fetal intrauterine distress. Among the indicators of the modified BPS, the scores for fetal movement, muscle tone, and amniotic fluid volume in the distress group were lower than those in the non-distress group (P < 0.05), whereas there was no statistically significant difference in the score for fetal breathing movements between the two groups (P > 0.05). Compared with the non-distress group, the distress group showed significantly lower values in modified BPS, MCA-PI/ UA-PI (P < 0.05), while demonstrating a significantly higher UA-S/D (P < 0.05). Additionally, the distress group was associated with a significantly higher NST classification (P < 0.05). In comparison to the non-distress group, the distress group showed significantly lower values for modified BPS and MCA-PI/UA-PI, while UA-S/D was significantly higher (P < 0.05). Additionally, the distress group exhibited a higher NST classification compared to the non-distress group (P < 0.05). ROC curve analysis revealed that among the single detection indicators, NST had a sensitivity of 77.3% and specificity of 63.0%; modified BPS had a sensitivity of 72.7% and specificity of 88.9%; UA-S/D had a sensitivity of 81.8% and specificity of 84.4%; and MCA-PI/UA-PI had a sensitivity of 86.4% and specificity of 90.4%. Among the combined detection strategies, modified BPS combined with NST achieved a sensitivity of 90.9% and specificity of 75.6%; modified BPS combined with MCA-PI/UA-PI yielded a sensitivity of 86.4% and specificity of 87.4%; modified BPS combined with UA-S/D showed a sensitivity of 81.8% and specificity of 88.9%; and UA-S/D combined with MCA-PI/UA-PI demonstrated a sensitivity of 81.8% and specificity of 92.6%. Among the single detection indicators, MCA-PI/UA-PI demonstrated favorable sensitivity and specificity. In combined detection, the combination of modified BPS and NST performed notably well in sensitivity, while UA-S/D combined with MCA-PI/UA-PI demonstrated relatively high specificity.Conclusion The modified BPS, UA-S/D, MCA-PI/UA-PI, NST and combined all have diagnostic value for fetal intrauterine distress. Combined diagnosis shows potential to further improve diagnostic performance. Different combinations show different characteristics in sensitivity and specificity, allowing clinicians to choose an appropriate strategy based on the need to either minimize missed diagnoses or control misdiagnoses.