The invention discloses a detection method of movement direction of a linear motor rotor and a direct-driving type wave power generation system. The system comprises a wave power generation simulation module used for simulating wave power generation processes in actual sea conditions, a no-position rotor movement direction detection module used for detecting movement of a permanent magnetic linear motor rotor, an information acquisition module used for acquiring current and voltage signals at a motor side and a net side, an electric energy processing rectification module and an electric energy processing inversion grid-connection module. The electric energy processing rectification module and the electric energy processing inversion grid-connection module are used for rectification of three-phase output of the wave power generation simulation module and carrying out inversion grid-connection to a big power grid according to a grid-connection condition. According to the invention, movement directions of the permanent magnetic linear motor rotor can be effectively detected; the whole processes of output, rectification and grid connection into the big power grid of electric energy of wave power generation can be simulated; and the system and the method have higher research value and meanings for development of wave energy power generation.