To analyze the risk factors of placenta implantation, and to observe the ultrasound imaging findings of the women with different degrees of placenta implantation. Methods: During the period from March 2017 to September 2019, 150 pregnant women with placenta implantation were enrolled in research group, and another 150 normal pregnant women were enrolled in control group. All the women were given prenatal ultrasound examination and the risk factors of placenta implantation were analyzed. According to different degrees of placenta implantation, the women in research group were divided into mild group (adhesion type) and severe group (implantation type and penetration type). The ultrasound image findings of the women were compared among these groups. Results: There were significant differences in age, pregnancy times, body mass index before prepregnancy, labor times, history of induced abortion, history of previous cesarean section, multiple pregnancy rate, and placenta previa rate of the women between the research group and the control group (P<0.05). Multivariate logistic regression analysis showed that history of induced abortion, history of cesarean section, history of placenta previa, and history of intrauterine surgery were the risk factors of placenta accreta (P<0.05). There were significant differences in placenta location, placenta thickness, posterior low vocal cord, bladder line, internal echo of placenta, and blood flow signal of placenta base of the women between severe group and mild group (P<0.05). Conclusion: The risk factors of placenta implantation include induced abortion number, previous cesarean section history, placenta previa history, and intrauterine operation history. There are differences in ultrasound imaging findings of the women with different degrees of placenta implantation. Differential diagnosis, prevention and treatment of placenta implantation should be conducted based on the risk factors and ultrasound imaging findings of placenta implantation in clinic.