Utilizing long-path differential optical absorption spectroscopy technique, air pollutants from ship emission in typical shipping channel area of the downstream of Huangpu River were measured with hightemporal resolution. It is found that SO2 concentration can increase by 2 to 4 times instantaneously and reach more than 10×10-9 due to the significant impacts of ship plume. However, since its emission sources are more complicated, the variation of NO2 concentration is relatively gentle, and under the influence of vehicle emission nearby, the diurnal variation of NO2 concentrations shows obvious bimodal characteristic. Affected by ship flow, SO2 concentration is relatively high in daytime. The analysis of the impact of human activities demonstrats that the NO2 concentration dropped by more than 30% during the Spring Festival holidays compared with that before and after, and even decreased to 50% after the first-level response to major public health emergencies of COVID-19. It is worth noting that the response of SO2 concentration to the control measures of COVID-19 and holiday effect is not so obvious as that of NO2 due to the differences of ship activity. However, the typical high emission value of SO2 concentration has shown a downward trend year by year.