A 256×256 HgCdTe APD hybrid focal plane array （FPA） with 30μm pixel pitch was prepared by B ion implantation n-on-p planar junction technology based on MW HgCdTe material grown by LPE. The performance parameters such as gain， dark current and noise factor were characterized and analyzed at liquid nitrogen temperature. The results show that the average gain of HgCdTe APD focal plane chip is 166.8 and the gain non-uniformity is 3.33% under - 8.5V reverse bias； Under 0 ~ - 8.5V reverse bias， the gain normalized dark current of APD device is 9.0×10^-14A~1.6×10^-13A， the noise factor F is between 1.0 and 1.5. In addition， the imaging demonstration of HgCdTe APD focal plane is carried out， and a good imaging effect is obtained.