A satellite information operation method of a GPS device includes following steps. An antenna module is provided, so as to receive a satellite signal. A signal processing circuit is provided, so as to perform an analog-to-digital conversion on the satellite signal and obtain a plurality of first digital data. A memory with a comparison table stored therein is provided, and the comparison table records corresponding relations between a plurality of second digital data and a plurality of return values. A CPU is provided, which groups the first digital data in sequence by using a bit number of any second digital data in the comparison table, obtains each of the second digital data consistent with each group of first digital data through comparison, and looks up a corresponding return value according to each of the second digital data obtained through comparison to continue the operation according to the obtained return value.