The invention relates to the field of mobile communication, and aims to provide a filtering method for optimizing parameters by adopting a 
genetic algorithm and a nonlinear convex 
programming theory. Compared with the conventional digital 
wireless relay amplification equipment application technology, the method comprises the following steps of: transmitting digital 
baseband global system for mobile communications (
GSM) transmitting signals to a digital 
GSM filter for frequency selecting 
filtration, optimizing and calculating the parameters of the filter in advance according to the 
genetic algorithm and the nonlinear convex 
programming theory in the process of outputting the filtered 
GSM baseband signals, and performing frequency selecting 
filtration on the GSM low-range digital 
baseband signals by using the novel GSM filter. According to the method, parameter symmetry and 
linear phase characteristics are not strictly required but compromised by using a series of cost functions, so that the limited degree during parameter optimization is broadened; and by introducing the 
genetic algorithm for solving nonlinear planning, the optimization effect is further promoted, so that the design result is greatly superior to that of the prior art.