The invention provides a basalt fiber composite material and a preparation method thereof. The method comprises the following steps: mixing epoxy resin and cyanate ester resin by stirring according toa proportion, adding a flexibilizer, then adding a curing catalyst, and carrying out mixing by stirring to form epoxy resin toughened and modified cyanate ester resin; preparing the epoxy resin toughened and modified cyanate ester resin and basalt fibers into a prepreg; and carrying out layering and curing to obtain the basalt fiber composite material. The mechanical performance and the heat resistance of the prepared basalt composite material are greatly enhanced, and the cost is reduced. The basalt fiber composite material can be widely applied to the fields of industry, buildings, automobiles, aviation and the like.