Objective To analyze the effects of Ritodrine Hydrochloride treatment on serum progesterone (P), pregnancy-associated plasma protein-A (PAPP-A), carbohydrate antigen 125 (CA125) levels and effects on pregnancy outcomes for threatened miscarriage patients,provide reference for clinical treatment. Methods A retrospective analysis of the clinical data of 80 patients with threatened miscarriage admitted to Wuchuan Maternal and Child Health and Family Planning Service Center from January 2020 to January 2021 was done, according to different treatment methods, they were divided into the group A (Magnesium Sulfate treatment) and the group B (Magnesium Sulfate+Ritodrine Hydrochloride treatment), 40 cases in each group, until the uterine contractions and vaginal bleeding stopped, and then continued intravenous drip for 12 h. The time to disappearance of uterine contractions, the time to stop vaginal bleeding, and the time to prolong pregnancy were compared between the two groups, serum levels of interleukin-6 (IL-6), interleukin-10 (IL-10), interleukin-17 (IL-17), hormones and CA125 in the two groups of patients before and after treatment, as well as the success rate of miscarriage protection and the occurrence of adverse reactions in the two groups of patients were compared. Results The disappearance time of uterine contractions and vaginal bleeding in the group B were shorter than those in the group A, and the prolonged pregnancy time was longer than that in the group A; after treatment, the serum levels of IL-6, IL-17 and CA125 in the two groups were lower than those before treatment, and the group B was lower than the group A; after treatment, the serum levels of IL-10, P and PAPP-A in the two groups were higher than those before treatment, the group B was higher than the group A; after treatment, the success rate of abortion in the group B was higher than in the group A; the total incidence of adverse reactions in the group B was lower than in the group A (all P<0.05). Conclusion Ritodrine Hydrochloride in the treatment of threatened miscarriage can shorten the disappearance of uterine contractions and the cessation of vaginal bleeding, prolong the pregnancy time, reduce inflammatory factor levels, improve the patient's hormone level, and improve the success rate of abortion, with high safety.