Abstract: DCB is the main error term while measuring the total electron content of the ionosphere based on the GNSS dual-frequency beacons.A method is proposed in this paper to estimate the GNSS receiver DCB by measuring the simulated TEC from GNSS simulator.Hardware-in-the-loop experiment has been carried out to test the validity of the proposed method.The results show that the average DCB of the tested GNSS receiver was about16.067 ns with the accuracy of about 0.14 ns.It proves the effectiveness of the presented method,which could be a useful way in GNSS receiver performance evaluation and calibration.