Abstract We propose a time accuracy measurement method for low-sampling data acquisition equipment. We introduce the measurement principle and data acquisition process of this method, and give results of the time accuracy for a low-sampling data collector equipment with an example of earthquake department. The results show that this method can improve the time measurement accuracy of low-sampling data acquisition equipment to milliseconds. This method can be used in the test of timing accuracy of geophysical observation data collector with linear relationship between input and output.