The invention discloses warp knitting composite geotechnical cloth. The cloth is prepared from, by weight, 30-50 parts of glass fibers, 20-40 parts of viscose fibers, 20-30 parts of cellulose acetatefibers and 5-10 parts of filler. Meanwhile, the invention further discloses a preparing method of the warp knitting composite geotechnical cloth. Compared with a traditional technology, the warp knitting composite geotechnical cloth is small in thickness, light in weight, high in strength, rough in surface, not prone to sliding, easy to construct and good in use effect.