The invention discloses an adaptive underwater sound decision feedback equalization method based on a single vector sensor. The method comprises steps that, signal synchronization for a sound signal received by the vector sensor is carried out; electronic rotation synthesis is exerted on a horizontal vibration velocity signal, and then weight synthesis of the horizontal vibration velocity signal and a sound pressure signal is carried out to acquire a sound pressure and horizontal vibration velocity synthesis signal; the sound pressure and horizontal vibration velocity synthesis signal and a vertical vibration velocity signal are respectively demodulated to a base band, the base band signal is inputted to a decision feedback equalizer; a feed-forward end of the decision feedback equalizer is embedded with a phase-locked ring, an inputted base band signal firstly enters the phase-locked ring; equal-gain combination of the sound pressure and horizontal vibration velocity synthesis signal and the vertical vibration velocity signal is carried out; inter-code interference generated for a symbol in detection is estimated by a feedback filter and subtracts with output of a forward-direction filter to realize inter-code interference inhibition, and emission signal recovery is further realized. Through the method, an error rate can be reduced, and communication system robustness is improved.