In the past few decades, 3D hydroelastic theory, an important branch of ship mechanics, has been developing dramatically. It offers a fluid-structure interaction method calculating response of structure of ship or offshore platform directly, which plays an significant role in the evaluation of wave loads on maritime structures. For platform with multiple modules, it is not only referred to loads on modules themselves but also to connectors’ loads between modules for their performance prediction. Absolutely, the 3D hydroelastic method described here can solve this problem accurately and directly. In this paper, 3D hydroelastic software, named COMPASS-THAFTS, has been developed by CSSRC and CCS on the basis of 3D hydroelastic theory initially established by Wu (1984). This software is very proper for designers and researchers of offshore structures because of its convenient and fast processing function. The COMPASS-THAFTS software mainly contains two modules, frequency-domain module and time-domain module. In this paper, we will focus our attention on introduction of integrated framework and processing functions in frequency domain module of COMPASS-THAFTS. Taking a certain offshore platform as application object, the 3D hydroelastic responses are calculated and the results are processed, and finally, the internal rules of data are analyzed. In subsequent work, some new modules, such as mooring module, will be integrated into COMPASS-THAFTS.