A three-dimensional imaging method based on a superconducting nanowire photon detection array, the method comprising: providing superconducting nanowire single-photon detectors, SNSPDs, as array elements to form a superconducting nanowire photon detection array, placing the array elements at a superconducting low temperature, and biasing the array elements to be in a state slightly lower than a superconducting critical current of the array elements; providing a lens array as an optical alignment system, and splitting light generated by a pulsed laser into a plurality of beams with the same number as that of the array elements; irradiating the surface of an object with the plurality of beams, receiving light beams reflected by the surface of the object through the lens array and converging the plurality of reflected light beams to the superconducting nanowire photon detection array to generate voltage pulse signals; converting the voltage pulse signals into current pulse signals; recording a round-trip time of each photon; integrating current pulse signals outputted by the array elements over a period of time to obtain a total integrated charge, obtaining a number of photons absorbed by the array elements by a corresponding relation between the total integrated charge and the number of photons; calculating gray values of picture elements based on the number of photons absorbed by the array elements; and plotting a gray-scale image by taking the array elements as pixel points of the grayscale image, calculating a distance between the object and the pixel points according to the round-trip time of each photon, and reconstructing a three-dimensional image of the object according to the gray-scale image and the distance between the object and the pixel points. providing superconducting nanowire single-photon detectors, SNSPDs, as array elements to form a superconducting nanowire photon detection array, placing the array elements at a superconducting low temperature, and biasing the array elements to be in a state slightly lower than a superconducting critical current of the array elements; providing a lens array as an optical alignment system, and splitting light generated by a pulsed laser into a plurality of beams with the same number as that of the array elements; irradiating the surface of an object with the plurality of beams, receiving light beams reflected by the surface of the object through the lens array and converging the plurality of reflected light beams to the superconducting nanowire photon detection array to generate voltage pulse signals; converting the voltage pulse signals into current pulse signals; recording a round-trip time of each photon; integrating current pulse signals outputted by the array elements over a period of time to obtain a total integrated charge, obtaining a number of photons absorbed by the array elements by a corresponding relation between the total integrated charge and the number of photons; calculating gray values of picture elements based on the number of photons absorbed by the array elements; and plotting a gray-scale image by taking the array elements as pixel points of the grayscale image, calculating a distance between the object and the pixel points according to the round-trip time of each photon, and reconstructing a three-dimensional image of the object according to the gray-scale image and the distance between the object and the pixel points.