A quantum polarization-based multidimensional information detection device and method belongs to the laser radar technology field, and is used for solving the problem in the conventional target identification field that a long-distance weak signal echo encounters a sensitivity limit. The quantum polarization-based multidimensional information detection device and method of the present invention is characterized in that a synchronous control module generates a synchronous signal to drive a laser to generate a pulse signal, at the same time outputs the synchronous signal to a polarization state encoder to carry out the horizontal, vertical, diagonal and antidiagonal pseudorandom pulse sequence modulation; the laser after the modulation is carried out the collimation and beam expanding by an emission optical device to irradiate a target, and an echo signal is radiated to a reception optical device and then is divided into four signals by three optical splitters to pass four single-photon detectors Gm-APD respectively; a synchronous signal processor obtains an echo pulse sequence according to the pulse signals detected by the four single-photon detectors Gm-APD, and obtains the multidimensional information of target distance, intensity and polarization according to the echo pulse sequence and the synchronous signal. The quantum polarization-based multidimensional information detection device and method of the present invention is used for the detection of the laser radar long-distance weak signals.