Dolphins don't study well in the fourth grade. Dolphin thinking is monotonous in class, and there are not enough teachers. Dolphins' self-study form is relatively simple and less attractive to children. The pre-trial mechanism of dolphin thinking is not perfect. There is no pre-trial function at present. Although there are exercises after class, which will be corrected by teachers and fed back to parents, compared with other similar institutions, the limitations of dolphin thinking system function are obvious. Dolphin thinking teachers have a high turnover rate and often need to change teachers. Teachers only need to meet the bachelor's degree to apply. The statement of famous universities cannot be verified, and the transparency of teachers is not enough.