The invention relates to a low-pressure casting process for a turbine shell of a turbocharger. The low-pressure casting process comprises the following steps of a, manufacturing an upper formwork shell and a lower formwork shell; b, manufacturing sand core components; c, painting; d, assembling, and completing formwork manufacturing; e, smelting alloys; f, pouring a casting mold in a low-pressure casting way; and g, opening a box to clean a casting after the casting is solidified and cooled to obtain a turbine shell casting. The turbine shell of the turbocharger, produced according to the low-pressure casting process, is high in mechanical property, long in service life, high in metal availability, and low in casting cost, and energy consumption is reduced, so that the low-pressure casting process conforms to the national policy of unit energy consumption reduction.