Purpose: As a global public health event, COVID-19 has become a major source of stress. Under the influence of COVID-19, people’s psychological adjustment is worthy of attention. As proposed by previous researchers, appraisal and coping played an important role in potential stressful event like COVID-19. To understand people’s cognitive and behavioral reaction during this special period, as well as the psychological influence caused by COVID-19, this study investigated the feature of and the relationship among controllability appraisal, forward focus coping, trauma focus coping, depression and anxiety. Based on previous studies and theories, a multivariable multiple mediation model was established, in which coping was supposed to mediate the relationship between controllability appraisal and depression/anxiety. Methods: Researchers collected 1372 online questionnaires from 13 provinces on February 7th. Apart from demographic information such as age and gender, the Stress Appraisal Measurement scale, the Perceived Ability to Cope with Trauma scale, CES-D 11 and GAD 7 were used to measure target variables. SPSS 23.0 was used to analyze descriptive statistics, the Cronbach α coefficient and the multiple collinearity. A latent variable structural equation model analysis was conducted through Amos 21.0 to testify the purposed multivariable multiple mediation model. Results: The proposed multivariable multiple mediation model was approved statistically: X2/df = 6.31, RMSEA = 0.06, IFI = 0.93, CFI = 0.94, GFI = 0.94. The results showed that: (1) Controllable-by-self negatively predicted depression and anxiety, but controllable-by-others did not predict depression/anxiety; (2) Controllable-by-self positively predicted forward focus coping, but did not predict trauma focus coping; (3) Controllable-by-others positively predicted both forward focus coping and trauma focus coping; (4) Forward focus coping negatively predicted depression/anxiety while trauma focus coping presented a positive prediction. (5) Forward focus coping was a mediator between controllable-by-self and depression/anxiety; (6) Trauma focus coping was a mediator between controllable-by-self and depression/anxiety as well as between controllable-by-others and depression/anxiety. Conclusion and Discussion: To summary, the proposed multivariable multiple mediation model was partially support and revealed a complicated pattern among variables. This study explored and discussed the complex mechanisms and effects of controllability appraisal, coping and psychological adjustment during COVID-19. Future research may focus on the dynamic process of appraisal, coping and adjustment through lunching longitudinal studies. The quantitative and objective measure of coping flexibility is also of vital importance in order to understand the mechanism and influence of different coping strategies. The antecedent variables of appraisal should also be inquired to understand the psychological effects caused by COVID-19 comprehensively.