Aiming at the problem of high frequency noise interference in the ECT data acquisition system，onthe basis of analysis of the ECT system data acquisition and control principles，we designed an improved distributedalgorithm FIR low-pass digital filter combined with FPGA technology and digital filtering principle. The samplingfrequency of the filter is 1 .5 MHz，the pass band cutoff frequency is 20MHz，and the design method is windowfunction. We used the FDATooI toolbox in Matlab to extract and quantify the filter coefficients and the Quarters tosimulate the simulation. Experimental results showed that the FIR digital filter can achieve the filtering function ofthe high frequency signal in the data acquisition system. Compared with the traditional DA algorithm，it has theadvantages of small resource consumption and high acquisition speed and some other characteristics.