Autism Spectrum Disorder (ASD) is a developmental disorder with an increasing incidence, and patients with ASD may require treatment lasting for a lifetime. Researchers found that the content of tryptophan, glutamate, and other substances increased significantly in the blood of autistic patients, so early diagnosis and accurate typing treatment are necessary. In our project, we constructed biosensors through genetic engineering to detect the content of tryptophan and glutamate in the body for the early screening of autism. What’s more, the SLC7A5 levels are improved by building engineered probiotics to achieve the treatment of autism. We hope that our project will shed light on the possibility and practicability of the diagnosis and treatment of autism at an early stage.