Abstract: The question of information coding real time compression in quantization process was studied. On the basis of generalizing the principle of difference quantization and analyzing information entropy in data acquisition, coding bits of ADC were decreased, and coding compression in the quantization process was achieved. By analysis of coding compression method, analysis of information entropy in data acquisition and illustration of coding compression, it was showed that the method has obvious real time compression effect. The quantization precision was improved by subdivision error method. At the same time structures of ADCs and data acquisition systems were simplified, and the efficiency of information transmission in data acquisition was raised.