The invention relates to a method for manufacturing a high-voltage large-power thyristor by adopting a sintering process. The method comprises the following steps of preparing a process environment, ultrasonically washing, rinsing a silicon chip, washing a quartz frame and a quartz lead, diffusing aluminum on the silicon chip, diffusing boron on the silicon chip, oxidizing the silicon chip, performing primary photoetching, diffusing phosphorus, cutting and rounding, sintering, evaporating, forming alloy, performing secondary photoetching, shot blasting and grinding corners, performing spin etching, gluing for protection and encapsulating. Compared with the prior art, the method has the beneficial effects that the boron diffusion and the aluminum diffusion are adopted for manufacturing the chip, so that the front edge of a PN junction is enabled to be smooth; by adopting the novel sintering technology, the sintering deformation is small, firmness in binding is realized, and a diffusion parameter is stable and invariable; by adopting the ultraclean process environment and a precise washing method, the minority carrier life is long through excellent washing reagent; the diffusion is controlled by adopting a computer, and the corners are mechanically ground and blasted, so that the consistency of product parameters is guaranteed, and reliability in use can be realized; the manufacturing cost is low, the rate of finished products is high, and each technical performance can reach the level of a similar imported product.