The invention discloses a 
graphene nano sheet and SnS2 composite nano material and a synthesis method thereof. The 
composite material is characterized by being formed by compounding a 
graphene nano sheet and a SnS2 nano material, wherein the 
substance amount ratio of the 
graphene nano sheet to the SnS2 nano material is 1:1-4:1. The preparation method comprises the following steps of: preparing a 
graphite oxide nano sheet from 
graphite by using a chemical oxidation method, then dissolving L-
cysteine into deionized water, adding stannic 
chloride, and dissolving the stannic 
chloride with full stirring, wherein the 
molar ratio of the L-
cysteine to the stannic 
chloride in the solution is 6:1-12:1; and adding the 
graphite oxide nano sheet into the solution, performing ultrasonic treatment so that the 
graphite oxide nano sheet is fully dispersed in the 
hydrothermal reaction solution, and synthesizing the graphene nano sheet and SnS2 composite nano material by a one-step hydrothermal method, wherein the 
mass ratio of the graphene nano sheet to the SnS2 nano material in the 
composite material is 1:1-4:1. The method has the characteristics of mild reaction condition and simple process. The synthesized graphene nano sheet and SnS2 composite nano material serving as an 
electrode material of a 
new energy battery or serving as other materials has wide application.