Objective To investigate associations among auditory processing (AP), working memory, and language function in preschool children with developmental language disorder (DLD), and to analyze the mediating role of working memory. Methods A prospective cross-sectional design was adopted. Forty-two children with DLD (DLD group) and 45 typically developing children (normal control group) were enrolled. The Diagnostic Receptive and Expressive Assessment of Mandarin-Comprehensive (DREAM-C), Preschool Auditory Processing Assessment Scale (PAPAS), Wechsler Intelligence Scales (Fourth Edition), and Conners Parent Symptom Questionnaire (PSQ) were used for evaluation. Correlations among scales were analyzed. The relationships among auditory decoding, working memory, and overall language function, as well as the mediating effect of working memory, were examined. Results Scores on all PAPAS dimensions and the proportion of children at risk for AP abnormalities were significantly higher in the DLD group than in the control group (P0.001). In all children, DREAM-C dimension scores were negatively correlated with PAPAS dimension scores (P0.05). In the DLD group, working memory was negatively correlated with total PAPAS score and scores for auditory decoding, auditory attention, and communication (P0.05). PSQ scores for conduct problems, learning problems, and hyperactivity index were positively correlated with total PAPAS score and scores for auditory decoding, auditory attention, communication, and hyperactivity-impulsivity (P0.05). The impulsivity-hyperactivity score was positively correlated with total PAPAS score and scores for auditory attention and hyperactivity-impulsivity (P0.05). The anxiety score was positively correlated only with the communication score (P0.05). After controlling for confounders, the auditory decoding score (b'=-0.431, P=0.009) and the working memory score (b'=0.437, P0.001) were independently associated with the DREAM-C overall language score. Working memory partially mediated the association between auditory decoding and overall language ability, accounting for 40% of the total effect. Conclusions Auditory processing in preschool children with DLD is closely associated with language, cognitive, and behavioral problems. Auditory decoding directly affects language function and indirectly influences it through working memory. PAPAS may serve as a convenient screening tool for clinical use.