NOVELTY - A dried carbon nanotube and inorganic acid are mixed, heated and washed by deionized water, filtered and vacuum dried, to obtain purified carbon nanotube. The acidified carbon fiber and carbon nanotube are obtained using purified carbon nanotube. The acylated carbon fiber and carbon nanotube are obtained using acidified carbon fiber and carbon nanotube. The carbon fiber is obtained using acylated carbon fiber and carbon nanotube. The obtained carbon fiber is mixed with polyimide resin, to obtain carbon nanotube-modified carbon fiber/polyimide resin composite material.    USE - Manufacture of carbon nanotube-modified carbon fiber/polyimide resin multidimensional hybrid composite material used in fields of mechanical, electronic, aerospace, wind power generation and transportation.    ADVANTAGE - The carbon nanotube-modified carbon fiber/polyimide resin multidimensional hybrid composite material is efficiently manufactured with excellent strength.    DETAILED DESCRIPTION - A dried carbon nanotube (0.1-1x 102 g) and inorganic acid (10-1x 104 g) are added for mixing, processed for 1-48 hours, stirred with ultrasonic wave of 1-120 kHz and centrifugal speed of 10-106 rpm, heated at 20-150 degrees C, reacted for 1-48 hours, diluted and washed with deionized water and vacuum filtration is performed with microporous membrane and vacuum dried at 25-150 degrees C for 1-48 hours, to obtain purified carbon nanotube. The dried carbon nanotube (0.1-1x 102 g) and purified carbon nanotube (0.1-1x 102) are mixed with strongly oxidizing acid, processed for 0-80 hours, stirred, heated at 25-120 degrees C, reflowed and reacted for 1-80 hours, diluted and washed by deionized water and filtered using microporous membrane and vacuum dried at 25-200 degrees C for 1-48 hours, to obtain acidified carbon fiber and carbon nanotube. The obtained acidified carbon fiber (0.1-1x 102 g) and carbon nanotube (0.1-1x 10 g) are mixed with acylation reagents, processed for 0-80 hours, stirred, heated at 25-220 degrees C, reflowed and reacted for 0.5-100 hours, and filtered and acylation reagents are washed, to obtain acylated carbon fiber and carbon nanotube. The obtained acylated carbon fiber (0.1-1x 102 g) and acylated carbon nanotube are mixed with diamine or polyamine (1-1x 104), processed for 0-80 hours, stirred, reacted at 25-200 degrees C for 0.5-100 hours, filtered, washed and vacuum dried, to obtain carbon fiber-grafted with carbon nanotube and amino. The obtained carbon fiber-grafted with carbon nanotube and amino group (0.1-1x 102 g) is mixed with polyimide resin, reacted for 0.1-24 hours, defoamed with ammoniated carbon nanotube reinforced component and reacted at 50-400 degrees C for 0.5-48 hours to obtain carbon nanotube-modified carbon fiber/polyimide resin multidimensional hybrid composite material.