Abstract: A noise reduction method of using multiple identical analog channels to oversample the CCD signal is investigated experimentally. This method is based on the irrelevant noise characters in each part of the CCD camera's analog channel. The noise distribution in the circuit is tested and the noise improving factors are 1.354 and 1.65 for the two parallel connections and three parallel connections respectively. The improving factor agrees with the theory value. Experiment shows that the improving factor decreases with the increase of the gain of the programmer gain amplifier in the analog channel. This phenomenon and the difference between the experiment value and the theory value of improving factor are analyzed. The power supply noise, higher AD conversion rate and temperature rising are the major factors of the difference.