This study explored the influence of the dynamic assessment of human--computer interactive games on children's language potential. Thirty-seven special children aged 3--7 years were selected to participate in the study. They were divided into three groups according to their scores on the Autism Behaviour Checklist: (1) a non-autism group, (2) a suspected autism group and (3) an autism group. In two stages of static and dynamic assessment, all three groups of children completed language tests under the conditions of no mediated prompt and mediated prompts, and the data generated in the game interactions were processed and analysed. The findings suggest the following: (1) static assessment may ignore children's language potential, while dynamic assessment can measure and differentiate children's potential language development ability; (2) children with ASD need more mediation prompts and are more likely to complete tasks with explicit mediation prompts; (3) children with ASD have weaker language potential, and children with suspected ASD or non-ASD children have homogeneous language potential; and (4) assessors should pay timely attention to and maintain children's learning status and psychological changes. This study demonstrates the importance of human--computer interactive games as a dynamic assessment tool to tap into children's language potential and to determine their proximal developmental zone, which has important implications for teachers in understanding groups with different language abilities.