Theory of mind (ToM) represents a complex ability, while persons with autism spectrum disorder (ASD) encounter difficulties in the processing of ToM. The present ToM-focused studies on adults with ASD report inconsistent results, possibly owing to the differences between tasks. For instance, different ToM-related tasks involve different cognitive abilities, but the development of these cognitive abilities is different among adults with ASD, thereby leading to different behaviors by the same individual with ASD in different tasks. Therefore, it is of vital significance to explore the potential reasons for inconsistencies in the existing studies based on the task classification perspective. Hence, this study primarily reviews the existing ToM tasks used in studies on adults with ASD; afterward, based on the forms and characteristics of the task, the current ToM tasks are classified into four categories-reading comprehension, perceptual scene comprehension, comprehensive scene comprehension , and self-other processing. Subsequently, a meta-analysis is undertaken to determine the difference in each ToM task category between the ASD group and the typically developing (TD) group. As a result, 110 research papers (including 3,205 adults with ASD and 3,675 TD adults) that fulfilled the stated criteria are examined in this study. The study findings suggest that adults with ASD demonstrate worse performance in terms of all four ToM task categories as compared to TD adults. Furthermore, compared with tasks of self-other processing and perceptual scene comprehension, adults with ASD perform worse in reading comprehension and comprehensive scene comprehension. This shows that the differences between tasks may exert a potential influence on the study results. Future studies should focus on different abilities involved in ToM processing and the choice of ToM tasks, in order to elucidate the critical problems of ToM in adults with ASD.