Abstract: The sensitivity,selectivity,accuracy and separability for the image pre-processing circuit of multi-sensor system are analysed completely and the upper bounds of the accuracy and sparability are obtained using the matrix norm.Those bounds expose the relations among the accuracy and separability,the condition number (Cond(b)) and deviation Wb of the design matrix and the diturbing random variable X,Which shows that the estimate of the accuracy can be restricted to a certain level by the control of Cond(b), W and X.