There always exist some challenges in long array column infrared Time Delay Integration(TDI) detecting system, such as large number of channels, high noise and power dissipation. To solve those problems mentioned above, a new solution was proposed to improve the performance of infrared TDI detecting system with Application Specific Integrated Circuit(ASIC) chip(eight-channel signal conditioning chip). Meanwhile, it helped to light the weight and reduce the system volume. In the system, the noise and dissipation both reduced to half than before. The average noise of system was 1.42 mV with power of 0.73 W. More higher integration was achieved by Readout Integrated Circuit(ROIC), design complexity and workload were reduced. It provides technical support and practical foundation for micro miniaturization aerospace remote sensing satellite development.