This paper deals with a multi-channel & diverse sampling rates signal acquisition system for the problem of multi-channel data acquisition card. At present, data acquisition card has only one sampling rate and one setting of data processing. So its application is not flexible. According to the difference of sampling signals, The system which is based on multirate signal processing technology uses fractional sampling rate conversion on each channel for realtime to find their the best sampling rates, and then to achieve the fastest speed and lowest power of operation in the whole system.