The invention discloses a transition metal sulfide / graphene composite material which is composed of a nano transition metal sulfide and graphene, wherein the transition metal sulfide is Ni2S3, NiS, FeS, FeS2, CoS, CoS2, CuS2, CuS, MnS or MnS2. Under the dispersion and loading actions of the graphene, the transition metal sulfide can be uniformly distributed and have small particle size, the stability and loop stability of the transition metal sulfide in the charging and discharging process can be effectively enhanced, and the composite material can be used as a lithium ion battery negative pole material. The invention also discloses a one-step low-temperature preparation method of the composite material, which has the advantages of simple technique, low cost, short cycle, low energy consumption and the like and is suitable for large-scale industrial production.