A method of producing a base compound for a liquid fluoroelastomer which is unaffected by the storage state of the added silica powder, and yields minimal fluctuation in the viscosity between production lots. Specifically, a method of producing a base compound for a liquid fluoroelastomer containing: (A) a linear fluoropolyether compound having at least two alkenyl groups within each molecule and having a perfluoroalkyl ether structure within the main chain, and (B) a hydrophobic silica powder, the method including: (1) heating the component (A) under normal pressure at a temperature of 50 to 100 ° C., (2) adding 20 to 60 parts by mass of the component (B) to 100 parts by mass of the component (A) that has been heated in step (1) while performing kneading to obtain a kneaded product, and (3) kneading the kneaded product obtained in step (2) at a temperature exceeding 100° C., either under conditions of heat and reduced pressure or under conditions of heat and pressure.