Designed and fabricated is a monolithically integrated high-speed and high-sensitivity optical coupler chip, which contains Nwell-Pepitaxial-Psubstrate model for the photoelectric detector (PD), the transimpedance amplifier (TIA) and the subsequent processing circuits. The PD model was analyzed and its frequency response was simulated, then operational transconductance amplifier (OTA) circuit was designed. The experimental results show when the temperature is 25℃ and the optical current is 12.2mA, the sensitivity of the TIA module can reach 2ns, and the response time of the entire chip is 205ns and 155ns. So it is suitable for high-speed and high-sensitivity intelligent control instruments and communication systems.