Abstract: Based on dynamic integration approach,the effects of main payloads measurement errors in SST-LL mode on Earth gravity model accuracy are analyzed quantitatively by simulated calculation.The results indicate that the gravity model error caused by inter-satellite range-rate of 1 μm/s and the one caused by non-conservative force error of 10-9 m/s2 are at the same level.The measurement accuracy of main payloads should be coincide each other.It is less helpful for improving the Earth gravity model by only improving one payload's measurement accuracy.