Silicon-organic hybrid photonic integration technology fully utilizes the advantages of large-scale integration of silicon photonics and the high electro-optic coefficient of organic polymer materials. This accords great application potential in high-performance integrated microwave photonics systems to it. This paper discusses a comprehensive optimal structural design and preliminary preparation of a silicon-organic hybrid integrated electro-optic modulator. The slit of the silicon slot waveguide is filled with electro-optic organic polymer. The optical field confinement factor reaches 0.32 when the structure of the slot waveguide is optimized. The optical wave field and radio-frequency electric field overlap considerably, thereby improving the electro-optic modulation efficiency. The tapered waveguide mode conversion structure is used to achieve low-loss coupling between the strip and slot waveguides with a acoupling efficiency of 99.55%. The frequency modulation response is addressed by analyzing the influence of the electrode length and width. The 3 dB bandwidth is optimized to 77 GHz, and the half-wave voltage-length product reaches 0.045 V·cm. The MASK used in manufacturing the modulator is designed based on the simulation results. Experiments involving the slot waveguide and the filling polymer in the slot waveguide are performed with good results.