Characteristics of brain development: Children's brain development tends to be mature, and the brain weight is 1250- 1350g, which is basically close to that of adults. The development of cerebral cortex shows that the inhibition process is stronger than the excitement process, which shows that the self-control ability is enhanced and the sleep time is correspondingly reduced. ● Characteristics of cognitive development: The characteristics of intellectual development are the improvement of acuity, the enhancement of perceived purpose and intention, the enhancement of initiative and stability of attention, and the ability to consciously concentrate. The development of thinking is manifested in the rational use of spoken words and the beginning of mastering written words. Memory develops from unintentional memory to intentional memory. Because learning requires most memories to be expressed in words, it promotes the development of logical memory. Due to the increasing interpersonal communication, expanding activities and increasing experience, primary school students' comprehensive analysis ability of objective things is constantly enhanced, and the obtained representations can be creatively processed and transformed, which promotes the development of imagination. ● Characteristics of emotional development: emotional expressions are rich, easy to express emotions, and gradually form high-level emotions such as love, hate, honor and disgrace, and the sense of morality and reason tends to deepen and stabilize. Characteristics of will development: school-age children's willpower is in the process of gradually strengthening, and junior students' will activities are unconscious, not lasting and impulsive, and learning needs to be urged. Senior students' will activities are obviously enhanced, and most children can overcome the difficulties in learning. ● Development characteristics of individual psychological characteristics: Children's psychological ability, temperament and personality have been cultivated and developed in primary school. In the class, students with different temperament and personality can be clearly found, such as some are enthusiastic and unrestrained, and some are quiet and introverted. After entering primary school, learning practice and interpersonal communication have greatly promoted the development of children's psychological activities. At this time, children have great plasticity, and the educational methods of teachers and parents and the surrounding environment will have a vital impact on the psychological development of school-age children.