Identifying a “core deficit” is essential for early detection and intervention in developmental disorders among children. However, the presence of a core deficit within autism spectrum disorder (ASD) continues to be unclear. Therefore, the purpose of this study was to examine the possibility of the core deficit in autism spectrum disorders. This study evaluated 543 children diagnosed with ASD by using Chinese version of the Psychoeducational Profile-Third Edition (CPEP-3). Structural equation modeling (SEM) was used to construct single-factor models (assuming the presence of a core deficit) and a multi-factor model (assuming the absence of core deficits) based on the assessed data, and then to compare the fit of the two types of models. Assessments revealed developmental delays and adaptive challenges among the children with ASD. The single-factor model assuming the “motor” domain as the “core deficit” showed a superior fit (CFI = 0.86, AIC = 356.47, ECVI = 0.66) than other single-factor models. The multi-factor model, which assumes no core deficit, provided a better fit and greater predictive accuracy (CFI = 0.87, AIC = 351.94, ECVI = 0.65) than all single-factor models. ASD is characterized by widespread developmental delays and adaptive challenges. While motor impairment may serve as an effective predictor of these issues, it does not fully account for the diverse and complex symptomatology observed in children with ASD. The symptoms in these children likely arise from multiple factors, which are not adequately explained by a single core deficit model.