The new dual-band infrared detector can be read out to design a weak signal readout circuit, the readout circuit integration time is adjustable, and has characteristics of low power consumption, low noise and high sensitivity.Using feedback enhanced direct injection readout circuit (FEDI) and high performance capacitive feedback transimpedance amplifier (H-CTIA) combining circuit pattern structure, and the switch circuit is adjusted by way of two adjacent pixels ,which share one of the amplifier circuit. This not only reduces the area which is occupied by an amplifier in the single pixel circuit, but also reduces the complexity of the circuit design. By integrating capacitor circuit and adjusting the sampling capacitor, the readout circuit can be achieved after the first integrator output mode and the side edge integral output mode. Combined with complementary S matrix coding regulatory principles to eliminate stray light circuit dark current noise, ultimately it can read out weak signals. In this study, TSMC 0.35um 2P4M technology taped the circuit area of the synthesized pixel unit of 35um × 35um, entered the photocurrent is 0.09pA ~ 48nA, the output signal to noise ratio can reach 72dB, high linearity response to 99.3%, ROIC accuracy has been greatly improved, which can meet the desired designing requirements.