This paper proposed a method to accurately calculate ADS-B report latency in order to improve the surveillance accuracy of Automatic Dependent Surveillance-Broadcast (ADS-B) for the ADS-B latency had great influence on the surveillance accuracy. The time interval of two adjacent reports and the relevant two adjacent aircraft positions could be calculated on the basis of Time Of Receiving (TOR) and content of ADS-B reports. Then the different latencies were calculated by differencing the two time intervals. Given that the Time Of Measure (TOM) as the initial report time or a certain interval time, all the subsequent latencies could be measured and corrected. The authors carried out the feasibility analysis using Microsoft Excel by randomly selecting a aircraft ADS-B reports in 15min, 25min and 45min for ADS-B reports. The results show that ADS-B surveillance accuracy has been greatly improved within 10 meters, which can meet the requirement of airport surface surveillance.