The invention provides an N-type SnSe thermoelectric material, belonging to the technical field of energy materials. The N-type SnSe thermoelectric material is composed of Sn, Se and Br atoms, and anatomic molar ratio of the Sn, Se and Br is 1:0.97-0.99: 0.01-0.03; the N-type SnSe thermoelectric material is monocrystalline, and unit cell parameters abc of a crystal are 11.48346 angstroms, 4.14846angstroms and 4.43524 angstroms respectively, and axial angles alpha, beta and gamma are 90 degrees; and a ZT value of the N-type SnSe thermoelectric material is 2.0 to 2.8. The N-type SnSe thermoelectric material prepared by the invention is monocrystalline, eliminates the influence of grain boundaries and impurities on electron transport, significantly improves the electrical performance, and realizes the improvement of thermoelectric performance of N-type material components of a thermoelectric device based on the SnSe crystals.