With the aim to improve the performance of an infrared detector and to enhance the characteristics of a Focal Plane Array(FPA), a capacitive-read infrared FPA with the structure of cantilever element in a fold-line leg and a long-line leg was designed. The thermal conductivity , thermo-mechanical sensitivity and the thermal time constant of the structure were discussed and optimized, then these parameters were set to be 3×10-7 W/K, 162 nm/K and 35 ms, respectively. The sensitivity of design is fast enough to satisfy the requirements of human eyes.Furthermore, the Noise Equivalent Temperature Difference( NETD) which is key for the FPA detection was discussed, and calculated result shows that the NETD of the designed FPA is 6 mK. A simulation for the NETD was also performed, which shows the NETD is 5 mK. Experiments indicate that the simulation result agrees with that of the calculation well and show that the NETD is small enough to satisfy the resolution for signal read-out. Finally, the capacitive-read FPA was fabricated based on silicon micromachining technology successfully.