The present invention discloses a system for testing microfluid which is made with a disposable disc. If the intra-line image data is being transmitted and no pixel data to be processed in the image data exists, no clock signal is supplied to the second image processing unit. The first processing unit calculates a non-access proportion of the data not been accessed for a preset time, according to the access times and then determines whether the non-access proportion is larger than a preset proportion, to generate the processing signal for controlling the at least storage unit to stay in the disable state or the standby state.