The invention relates to a preparation method of a B4C modified C/C-SiC brake material. According to the method, a vacuum pressure dipping method is used for introducing a B4C powder material in a three-dimensional needle carbon felt with the initial density being 0.4 to 0.6g/cm<3>; CVI (chemical vapor infiltration) and RMI (reaction melt infiltration) are combined for preparing the C/C-SiC brake material. When the B4C modified C/C-SiC brake material is used, on one hand, the B4C is used as a self heeling component for achieving the protection effects on the carbon fiber and a carbon base body; the inoxidizability of the material can be obviously improved; on the other hand, the B4C has higher specific heat capacity; the integral specific heat capacity of the material can be improved; the braking temperature can be effectively reduced; the material friction performance stability is improved.