A novel laser ranging method use Geiger mode APD (avalanche photodiode) arrays is introduced in this paper.In the proposed method，echo signal is received by APD arrays at gate mode，system fulfill photon detecting，start-point distinguish，determine the distance of target ultimately.The results show that with this method，we can get a higher precision，farther distance with less laser power，comparing with the traditional laser ranging methods.So a new thinking way for the laser ranging is provided.