To estimate the impact on emergency attendance for stroke and acute myocardial infarction (AMI) during the pandemic of COVID-19 in Beijing, China. Based on 17,123 and 8693 emergency attendance for stroke and AMI, an interrupted time-series (ITS) study was conducted. Since 01/24/2020, the top two levels of regulations on major public health have been implemented in Beijing. This study covered from 03/01/2018 to 06/03/2020, including 19 weeks of lockdown period and 99 weeks before. A segmented Poisson regression model was used to estimate the immediate change and the monthly change in the secular trend of the emergency attendance rates. The emergency attendance rates of stroke and AMI cut in half at the beginning of the lockdown period, with 52.1% (95% CI 45.8% to 57.7%) and 63.1% (95% CI 56.1% to 63.1%) immediate decreases for stroke and AMI, respectively. Then during the lockdown period, 7.0% (95% CI 2.5%, 11.6%) and 16.1% (95% CI 9.5, 23.1) increases per month in the secular trends of emergency attendance rates were shown for stroke and AMI, respectively. Though the accelerated increasing rates, there were estimated 1335 and 747 patients with stroke and AMI without seeking emergency medical aid during the lockdown, respectively. The emergency attendance for stroke and AMI cut in half at the beginning of the pandemic then had gradual restoration thereafter. The results hint the need for more engagement and communications with all stakeholders to reduce the negative impact on CVD emergency medical services during the crisis.