Abstract: In order to improve the shortcoming of the traditional multibeam data processing,a new method,which blends GPS height and heave to present the actual height at transducer,is studied.In the fusion,GPS height and heave need to be corrected to transducer by attitude correction firstly.Secondly,GPS height needs to be checked and modified by heave check and modification itself.In addition,filter methods are studied by comparing Buttworth filter and FFT spectrum analysis,the latter is chosen finally for extracting height-frequency signal from heave and low-frequency signal from GPS height,and blending a new height at transducer.The applications of the method in few experiments prove that it has higher accuracy relative to the traditional.