In the recent years, with the increase in the caesarean section rate, the incidence of caesarean scar pregnancy (CSP) has shown a significant upwards trend. We propose a novel, simple and rapid clinical and ultrasound (US) classification scoring system to assist in the early diagnosis of CSP. A total of 385 patients with CSP were included in the study. All patients were given a comprehensive score, iincluding clinical data (whether HCG is consistent with gestational age and vaginal bleeding) and US findings (linea a and b, gestational sac morphology, the presence of primitive cardiac tube beat, and color Doppler aspect). The scores were analysed by ROC curve analysis, and sensitivity and specificity were calculated. A score of 4 has a specificity of 91.7% and a sensitivity of 95.6% in diagnose CSP. The area under the ROC curve was 0.973. This scoring system may be a reliable tool for the early diagnosis of CSP and has the characteristics of being simple and rapid. For patients with a total score of ≥4 points, CSP is suggested, and early clinical treatment can be carried out, while patients with a score of less than 4 points can temporarily retain pregnancy and be closely followed up.