Background At the end of 2019, the Coronavirus disease 2019 (COVID-19), with highly infectious, transmits rapidly. So it has caused people panic to a certain degree. Methods This cross-sectional study performed via an online survey run from January 30 to March 30, 2020. 1144 people in South China (287 of level 1 population, 121 of level 2 population, 160 of level 3 population, 576 of level 4 population ) were investigated. GAD-7 scale, PHQ-9 scale, and PSS-10 scale were used to evaluate the mental health status of different populations. Results Among 1144 subjects, the average GAD-7 score was 4(1,8), the average PHQ-9 score was 4(1,9), and the average PSS-10 score was 16(11,19). There were statistically significant differences in the scores of GAD-7 (H = 15.235, P <0.01), PHQ-9 (H = 9.265, P = 0.026), and PSS-10 (H = 8.435, P = 0.049) among different levels of population. In the score of GAD-7: The anxiety degree of the level 1 population is higher than that of the level 2 population and the level 4 population. The difference between the two pairs is statistically significant (Z = -2.932, -4.012, -2.949, P <0.005). There are significant differences in items of“becoming easily annoyed or irritable”, "seemingly terrible things will happen"(Z = -3.399 ~ -2.055, P <0.005); Score of PHQ-9: The depression degree of the level 1 population and the level 2 population is higher than that of the level 4 population, and the difference between the two pairs is statistically significant (Z = -3.38, -2.682, P <0.005). There are significant differences in items of "difficult to fall asleep or not awake", "feeling depressed" and other related items (Z = -2.885 ~ -2.003, P <0.005); Score of PSS-10: The stress degree of the level 3 population is higher than that of the level 1 population and the level 4 population (Z = -3.693 ~ -2.702, P <0.005). There are significant differences in items of "feel confident", "life are as expected", "the ability to control anger", "the things are all under control" and other related items (Z = -4.782 ~ -2.102, P <0.005). Conclusion There are differences in the effects of COVID-19 on the mental health of people with different identities. Appropriate psychological interventions should be provided for different populations in combination with their mental health status.