High-speed electro-optic modulator is one of the key components in broadband optical communication networks and microwave photonic systems. Compared with the legacy lithium niobate, the thin-film lithium niobate material has unique advantages in constructing high-performance electro-optic modulation chips with small size, broadband and low half-wave voltage due to its strong optical field confinement ability. In this paper, an electro-optical modulation chip with a 3dB bandwidth not less than 50GHz was developed based on thin-film lithium niobate materials, and a fully packaged thin-film niobate electro-optic modulators was realized by using an optical packaging scheme of horizontal edge coupling between optical fiber and waveguide and a radio frequency packaging scheme based on 1.85mm coaxial connectors. Measurement results indicate that the optical insertion loss of the packaged device is less than or equal to 5dB, the 3dB bandwidth is greater than or equal to 40GHz, and the RF half-wave voltage is less than or equal to 3V@1GHz.