Abstract: In order to study the influence of different noise levels on the physiological and cognitive performance of workers in the working environment, the physiological indicators such as diastolic blood pressure, systolic blood pressure, heart rate and heart rate variability were measured with noise level as independent variables. Meanwhile, cognitive performance indicators such as average reaction time and error rate of operators under different noise levels were measured. Origin and SPSS were used to carry out statistical analysis and model establishment. The results showed that: when the noise level was 35 db-75 dB, systolic blood pressure decreased first and then increased with the increase of noise level; when the noise level was greater than 75 dB, systolic blood pressure gradually increased; diastolic blood pressure, RRI and HRV decreased with the increase of noise level; heart rate HR increased with the increase of noise level; average reaction time and error rate of subjects increased with the increase of noise level. With the increase of noise level, the sympathetic nerve activity of the subjects increased, the cognitive performance decreased, and the adverse effects on the operators increased.