[Objective] To analyze the influencing factors of early diagnosis of children with developmental dysplasia of the hip (DDH) in northwest China， and to provide scientific basis for the formulation and implementation of DDH related public health policies. [Methods] A total of 325 children with DDH under 7 years old admitted to Xijing Hospital from January 2011 to December 2020 were retrospectively enrolled as the research subjects. According to the age of the children at diagnosis, they were divided into early diagnosed group (diagnosis age 0～6 months) and late diagnosed group (diagnosis age 7～84 months). The investigation included basic information, family information and diagnosis and treatment information of the children with illness. Spearman correlation analysis was carried out on the relationship between different diagnosis months and ultrasonic Graf classification and image crown classification, and then univariate analysis and multivariate logistic regression analysis were carried out according to the grouping. [Results] A total of 325 patients (432 hips) were included, including 72 cases in the early diagnosed group and 263 cases in the late diagnosed group. There was a weak negative correlation between the age of diagnosis and ultrasonic Graf classification in the early diagnosed group (r = -0.284, P = 0.016). There was a weak positive correlation between the age of diagnosis and Crowe classification in the late diagnosed group (r = 0.144, P = 0.023). The results of multivariate logistic regression showed that family economic condition, mother's education level and whether to carry out early hip screening were independent influencing factors for the early diagnosis of DDH children. [Conclusions] There was a weak negative correlation between the diagnosis age of patients under 6 months and ultrasonic Graf typing, and a weak positive correlation between the diagnosis age of patients over 7 months and imaging Crowe typing. Family economic condition, mother's education level and whether to carry out early hip screening were the independent influencing factors for early diagnosis of DDH in northwest China.