Abstract: When the existing method of pre-stored weight coefficient generation is used for linear array imaging sonar, it is necessary to call Block Memory IP core to pre-store all weight coefficients in field programmable gate array (FPGA) for beamforming, which causes excessive utilization of random access memory (RAM) resources in hardware. An improved method based on CORDIC algorithm to generate weight coefficients in real time is proposed. By pre-storing a small amount of beam angle values and using Multiplier and CORDIC IP core, this method can generate the weight coefficients in real time and reduce the RAM resource by 77%. Besides, this method can dynamically load the weight coefficients at different sound speeds for beam-forming, and maintain a high computational efficiency. Through ISE Synthesize, Map and Place & Route, this method can effectively balance the occupancy rates of RAM resources and logical resources, saves FPGA cost and has good engineering application value.