Multiple studies have examined learning and training for autistic students to improve their quality of life by using eXtended-Reality (XR) technologies, which mainly include virtual reality (VR), augmented reality (AR), and mixed reality (MR). Nevertheless, little is known about how technical features and technology affordances of the XR environment are used and addressed in these studies. In this article, we had reviewed 66 empirical studies regarding XR for autistic individuals and examined the corresponding research designs from 3 major dimensions, namely, autonomy (i.e., the degree of freedom users have), human-computer interaction, and the sense of presence. We then investigated the technical features and technology affordances in these studies through the lenses of these three dimensions. Fifty-four (81.82%) studies used VR as their interventional tool, eleven (16.67%) studies used AR, and only one (1.52%) study used MR. Results showed that the use of different XR platforms is closely related to the technical features, technology affordances, and study characteristics. We further provided an extraction of the essentials that serve as a practical reference for educational researchers and practitioners to inspect the design and implementation of XR technologies in learning and training environments for autistic students.