Abstract With the increasing attention paid to preschool physical activity in recent years, physical activity load assessment of preschool children has evolved with the development of theory and the wide application of microelectronic technology. In this paper, relevant literature from PubMed, Web of Science, and CNKI database were collected and analyzed, aiming to provide review and updates on physical activity load assessment in preschoolers. Given the characteristics of children s physical activities, effective measurement methods should be chosen and integrated from these tools, to improve the accuracy and effectiveness of children s physical activity load assessment.