▎ 摘　　要

NOVELTY - Carbon fiber preform comprises multiple first structural units and multiple second structural units arranged in a laminated manner. The bottom and the middle part of the carbon fiber prefabricated body are provided with the first structural unit. The rest part of the carbon fiber prefabricated body is overlapped with the second structural unit. The first structural unit comprises 0 degrees unidirectional carbon fiber cloth, a first net tire, graphene paper and a second net tire. The second structural unit comprises 0 degrees unidirectional carbon fiber cloth, a third net tire, 90 degrees unidirectional carbon fiber cloth and the fourth net tire. The 0 degrees unidirectional carbon fiber cloth in the first structural unit at the bottom of the carbon fiber prefabricated body is used as the outermost layer of the carbon fiber prefabricated body. The fourth net tire in one second structural unit and 0 degrees unidirectional carbon fiber cloth in another second structural unit. USE - The carbon fiber preform is useful in preparing carbon/carbon composite material (claimed). ADVANTAGE - The method enables to prepare carbon fiber preform, which has reduced porosity of the high temperature part, increased heat conducting ability, and effectively solves the closed hole problem in the process of densifying the carbon fiber preform. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) a method for preparing carbon fiber preform; and (2) a method for preparing carbon/carbon composite material. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic representation of the first structural unit of the carbon fiber preform.