A method produces a polysilane by reacting at least two silane monomers and at least one alkali metal. The silane monomers have the following structural units: at least one aryl group, at least one alkyl group, at least one alkenyl group, and at least three halogen atoms. Wherein at least three of the halogen atoms are bonded to a silicon atom of one of the silane monomers, and the reaction step takes place in an ether-containing solvent, particularly preferably dioxane. The obtained polysilane has a high molecular mass and, at 100° C., a viscosity of 1,500 to 3,000 Pa·s. The polysilane is very suitable for being processed to form silicon carbide fibers and fiber composites.