The invention provides a solid state fermentation production method for prodigiosin by using an inert carrier. The method is characterized by comprising the following steps: preparing a seed liquid of Serratia marcescens; and inoculating the seed liquid into a solid state fermentation medium according to a volume mass ratio of 4-15 ml/100 g and carrying out culture for 24 to 48 h under the conditions of a temperature of 24 to 30 DEG C and relative humidity of 70 to 90% so as to obtain a solid state fermentation prodigiosin product; wherein the solid state fermentation medium is composed of the inert carrier, a carbon source, a nitrogen source, salt and water according to a mass ratio of 1: 0.5-3: 0.2-2: 0.01-0.05: 5-18.