The invention provides a method of manufacturing a thermoelectric device taking a simple substance powder as an initial raw material in a one-step and super fast mode. The method comprises the following steps of 1) preparing a raw material; 2) in selective laser fusion equipment, according to a needed electrode pattern and a thickness, through a laser, fusing, solidifying and shaping an electrode material so as to acquire an insulation substrate on which an electrode layer (1) is printed; 3) on the insulation substrate acquired from the step 2), according to thermoelectric arm sizes and a distribution of a designed device, through the laser, generating an n-type thermoelectric compound powder and a p-type thermoelectric compound powder in a in-situ mode; 4) using laser fusion solidification and then acquiring an n-type thermoelectric arm and a p-type thermoelectric arm respectively; and 5) according to the needed electrode pattern and the thickness, printing an electrode layer (2) on the n-type thermoelectric arm and the p-type thermoelectric arm and acquiring the thermoelectric device. By using the method of the invention, tedious intermediate links during a traditional thermoelectric device manufacturing technology process are effectively avoided, and simultaneously, problems that a yield and a raw material utilization rate are low in a traditional welding and assembling technology are overcome.