Long-short carbon nanotube reinforced and toughened fiber composite material and preparation method thereof

The invention provides a long-short carbon nanotube reinforced and toughened fiber composite material and a preparation method thereof. The preparation method provided by the invention comprises the following steps: a) mixing short carbon nanotubes, thermosetting resin and an additive to obtain resin-based slurry; b) pouring the resin-based slurry into a fiber preform, and curing and molding to obtain the long-short carbon nanotube reinforced and toughened fiber composite material, wherein the fiber preform comprises an upper fiber cloth layer, a long carbon nanotube fiber yarn layer and a lower fiber cloth layer which are sequentially laminated and contacted; the long carbon nanotube fiber yarn layer is of a yarn-shaped structure formed by long carbon nanotubes; the length of the short carbon nanotubes is 0.5-3 [mu] m, and the average length is less than or equal to 2 [mu] m; the length of the long carbon nanotube is 50-1000 [mu] m, and the average length is gt; 100 [mu] m. According to the invention, the sp