Many researchers have tried to design and develop serious games with virtual characters to help children with ASD practice language communication skills. However, children with ASD often suffer from language communication disorders, especially often make mistakes in the use of personal pronouns. Games that use virtual characters usually do not take into account these inherent shortcomings of dysfunction in children with ASD, so they are not very effective in improving the language communication skills of children with ASD. In this study, an intervention system based on serious games which were integrated with the real avatars was designed for children with ASD to train their use skills in personal pronouns. By watching videos of themselves undergoing intervention in the game scenes, they can directly see “themselves” participating in the game, avoiding their abnormal brain mirroring functions. We hope that this avatar-based intervention system can help children with ASD overcome the dysfunction of the mirror neuron system and improve their express skills of personal pronouns.