The invention discloses a method for converting analog signals into digital information, and belongs to the field of signal processing. The method for converting the analog signals into the digital information aims to solve the problems that an existing signal sampling method is high in sampling rate, large in sampling data size, large in redundancy of sampling results and the like. The method comprises the following steps that (1) system parameters are configured and stored, (2) a starting order is given out, a measured signal module generates measured analog signals containing multiple frequency points, (3) the measured signals are divided into multiple channels of measured signals after passing through a power divider, (4) a trigger module generates rectangular pulse trigger signals, (5) multiple channels of different pseudorandom sequences are generated, (6) a signal conditioning module carries out random modulation on the input measured signals and the pseudorandom sequences, then the signals after the random modulation are input in a sampling module, (7) the sampling module captures the falling edges of the trigger signals and carries out even sampling on the pseudorandom sequences in the step (5) and the signals after the random modulation in the step (6), and (8) the frequency spectrum information in the signals is obtained. The method for converting the analog signals into the digital information is used for achieving the conversation from the analog signals to the information.