In a fluorosilicone rubber composition comprising (A) an organopolysiloxane having trifluoropropyl and (B) a silica filler, there are included (C) an organic peroxide of percarbonate type as a crosslinking agent and (D) a compound having a molecular weight of up to 10,000 and bearing in a molecule at least two substituents selected from among allyl, acryloyl, methacryloyl, epoxy and alkoxy groups as a co-crosslinking agent, whereby the vulcanization molding time is substantially reduced without detracting from physical properties.