Considering that precision of a data acquisition system corresponds to distortion less of signal transmitted by the system and the problem of time stability of the system, the paper put forward a new method of performance quantization of data acquisition system. The method regards data acquisition system as an open-loop linear time-invariant system and takes the system as a filter, whose input is the signal needed to acquire and output is the gathered signal. Then it reveals model parameter of channel by basic principle of LMS algorithm. Finally it calculates transmission characteristics of sinusoidal signal by use of received model parameter, so as to realize performance test of the data acquisition system. The mathematical simulation results of the system model and the quantization method showed that the quantization method and the system model respond to sinusoidal signal's response of the data acquisition system precisely, which can be used as a precision evaluation measure of actual data collection system.