To online detect, store and process nuclear signals with multiple forms and multiple frequencies, a compatible processing and analyzing system for nuclear signals based on ultrahighspeed data acquisition card was constructed. When the source signal is at pulse form, the system records signal with the mode of timedigitalconverting. When source signal is at continuous form, the system records signal with the mode of analogdigitalconverting. The processing procedures and algorithms were designed for various signal forms. The results for nuclear random process such as correlation function and power spectrum were effectively obtained.