The invention discloses a ternary vector array passive distance measuring method. The method comprises the steps that time domain filtering is carried out on signals output by three vector hydrophonesH1, H2 and H3; two vector hydrophones are selected; according to the sound pressure channel time domain filtering output outputted by two array elements, time delay estimation is calculated to estimate the target azimuth theta P; vector array synthesis is completed according to the target azimuth theta P; each vector combination is output to calculate the cross-correlation output of H1 and H2 andH1 and H3; the cross-correlation output is filtered; frequency bands are divided, and the filtered cross-correlation output of each frequency band is fused; and the time delay estimation is calculated based on the fusion result to complete the azimuth and distance estimation of a target. According to the invention, the method can fully use the sound field information; the time delay estimation accuracy is improved; the passive distance measuring accuracy is ultimately improved; and the method has a small amount of calculation and is highly practical.