The invention relates to a frequency planning method in GSM network. The frequency planning method in GSM network comprises the following steps: A, infrastructure data collection and collation; B, coverage optimization; C, neighboring optimization; D, optimization of same frequency and same BSIC (Base Station Identity Code); E, measured data collection and collation; F, interference matrix building; G, frequency model judgment; H, planning object selection; I, frequency planning; and J, cutting implementation according to frequency planning results; Step B is based on data of Step A, in Step B, a comprehensive general survey on the planning network is made, an antenna of the network, a repeater, an indoor distribution system and an extension system are understood and mastered comprehensively; and then coverage is optimized; Step G is based on data of Step A, through the analysis of network mean carrier frequency configure number and density of mean carrier frequency configure per unit area, the method for optimal frequency multiplexing model is acquired; Step G is based on data of Step A, according to requirements of the planned residential areas, a region, scale and capacity, the method for planning the region is acquired. The invention has high response speed.