Objective This study aims to investigate the correlation of an ultrasonic scoring system with intraoperative blood loss (IBL) in placenta accreta spectrum (PAS) disorders. Methods A retrospective cohort study was conducted between January 2015 and November 2019. Clinical data for patients with PAS have been obtained from medical records. Generalized additive models were used to explore the nonlinear relationships between ultrasonic scores and IBL. Logistic regressions were used to determine the differences in the risk of IBL ≥ 1,500 mL among groups with different ultrasonic scores. Results A total of 332 patients participated in the analysis. Generalized additive models showed a significant positive correlation between score and blood loss. The amount of IBL was increased due to the rise in the ultrasonic score. All cases were divided into three groups according to the scores (low score group:≤ 6 points, n = 147; median score group: 7?9 points, n = 126; and high score group:≥ 10 points, n = 59). Compared with the low score group, the high score group showed a higher risk of IBL≥ 1,500 mL [odds ratio, 15.09; 95％ confidence interval (3.85, 59.19); P ≤ 0.001] after a multivariable adjustment. Conclusions The risk of blood loss equal to or greater than 1,500 mL increases further when ultrasonic score greater than or equal to 10 points, the preparation for transfusion and referral mechanism should be considered.