The invention provides a method for preparing high-temperature-resistant structural SiC porous ceramics, belongs to the field of preparation of microwave-absorbing, environment-firendly, catalytic and biosensing semiconductor materials and energy sources and nuclear protective materials, and specifically relates to a method for preparing the SiC porous ceramics. The method aims to solve the problems that in an existing method for preparing the SiC porous ceramics, the pore size distribution and size of the porous ceramics are generally difficult to control, the specific surface area is small, and the mechanical strength of the high-porosity ceramics is low. The method includes the following steps: 1, kneading dough; 2, conducting fermentation and freeze drying to obtain porous dough; 3, conducting carbonization to obtain a porous carbon skeleton; 4, conducting sintering to obtain the high-temperature-resistant structural SiC porous ceramics. The method is mainly used for preparing the high-temperature-resistant structural SiC porous ceramics.