The main military applications of LADAR are first presented in this review.The requirements of LADAR on detector characteristics and the developing status of LADAR detectors are introduced in the second part.The characteristics and category of HgCdTe avalanche photodiode（APD）,the advantage of HgCdTe APD used as LADAR detector are discussed in the third part.The state of the art of HgCdTe APD for LADAR application is reviewed in the fourth part.In the last part the feasibility of developing HgCdTe APD LADAR detector in our country is discussed.