Preparation method for continuous SiC fibers capable of adjusting resistivity in large range

The invention discloses a preparation method for continuous SiC fibers capable of adjusting the resistivity in a large range. The preparation method comprises the following steps: (1) performing draw-spinning on a SiC ceramic precursor to obtain a proto fiber; (2) putting the proto fiber into a non-melting treatment device, vacuumizing, filling inert atmosphere, repeating the operation twice or more, and carrying out electronic beam irradiation crosslinking or active atmosphere crosslinking so that the gel content of the fiber is larger than or equal to 85 percent, thereby obtaining non-melting fibers; and (3) putting the non-melting fibers into a high-temperature furnace, feeding the inert atmosphere or a mixed gas of active atmosphere and the inert atmosphere, heating to 1,000-1,600 DEG C at the speed of 60-200 DEG C/h, and preserving the heat for 0.5-2.0 hours to obtain the continuous SiC fibers. The preparation method can be used for preparing the continuous SiC fibers with the adjustable resistivity in the large range of 10 -10 ohm.cm; the average diameter is uniform, and the mechanical performance is high. The method is simple in technology, can easily realize industrial production and is low in cost.