Cognitive effort is the core element of translation and interpreting process studies, but theoretical and practical issues such as the concept, characteristics and measurement of cognitive effort still need to be clarified. This paper firstly analyzes the concept and research characteristics of cognitive effort in translation and interpreting process studies. Then, based on the cost concept (internal cost, opportunity cost) and the reward concept (need for cognition, learned industriousness) of cognitive effort, it carries out multi-dimensional analysis of the characteristics of cognitive effort. Finally, it points out the enlightenment of multi-dimensional consideration of cognitive effort to translation and interpreting process studies.