The present invention relates to a method for preparing a thermoelectric thick film. The method includes: determining the brittle-to-ductile transition temperature of a thermoelectric material; rolling the blocky thermoelectric material within a temperature range above the brittle-to-ductile transition temperature and below a melting point; parameters of the rolling being as follows: the linear speed of rollers is 0.01 mm/s to 10 mm/s, preferably 0.1 mm/s to 5 mm/s, and the amount of pressing each time of the rollers is controlled at 0.0005 mm to 0.1 mm, preferably 0.001 mm to 0.05 mm; repeating rolling until a thermoelectric thick film with a specified thickness is obtained; and annealing the obtained thermoelectric thick film; the temperature of the annealing being 100°C to 800°C, preferably 300°C to 500°C, and the duration of the annealing being 10 to 500 hours, preferably 100 to 300 hours.