The Montessori method, developed by Italian physician and educator Maria Montessori, is an educational method based on sensory learning that respects the natural and individual development of each child. Applying this method in training students majoring in preschool education helps them innovate the way they organize activities, especially in forming quantity symbols for preschool children. This article introduces the process of guiding students at Lai Chau College to apply the Montessori method, to improve training quality and meet the requirements of educational innovation in the modern era.