Objective: To analyze the changes and clinical significance of pelvic floor muscle strength in primiparas in different age levels after different delivery modes. Methods: A total of 160 primiparas who were admitted to the hospital from August 2016 to August 2018 were enrolled in this study. The changes of pelvic floor muscle strength were compared in primiparas of unprotected delivery and traditional delivery at 6 weeks after delivery. Changes in pelvic floor muscle strength of primiparas of unprotected delivery and traditional delivery in different age levels were observed. Results: There was no significant difference in age, BMI, education level, occupation, labor and neonatal weight between primiparas of unprotected delivery and traditional delivery (P>0.05). The score of pelvic floor muscle strength, the anterior resting state, maximum contraction force, continuous contraction force and post-resting state of the unprotected delivery group were significantly higher than those of the traditional delivery group (P<0.05). The pelvic floor muscle strength of 23 to 30 years old primiparas of unprotected delivery at 6 weeks after delivery was significantly better than that aged less than 23 years old and greater than 30 years old primiparas (P<0.05). The pelvic floor muscle strength of 23 to 30 years old primiparas of traditional delivery at 6 weeks after delivery was significantly better than that aged less than 23 years old and greater than 30 years old primiparas (P<0.05). Conclusion: Both age and delivery mode affect the pelvic floor muscle strength of the primipara. The decrease of pelvic floor muscle strength in primiparas aged less than 23 years old and greater than 30 years old is more obvious. The pelvic floor muscle strength is obviously improved in primiparas of the unprotected delivery after delivery. It is recommended in clinical obstetrics and gynaecology to promote unprotected delivery for primipara aged less than 23 years old and greater than 30 years old.