The invention relates to a continuous multistage grinding and dispersing machine for graphene preparation. The grinding and dispersing machine comprises a shell, a primary grinding mechanism, a secondary grinding mechanism and a material conveying mechanism, wherein the upper end of the inner part of the shell is provided with the primary grinding mechanism, the lower end of the inner part of theshell is provided with the secondary grinding mechanism, the material conveying mechanism is arranged between the primary grinding mechanism and the secondary grinding mechanism, through holes are uniformly formed in the outer wall of the shell in the circumferential direction of the shell, the primary grinding mechanism comprises a primary motor, a rotating grinding disc, a fixed grinding disc, aconnecting ring and a guide ring, the secondary grinding mechanism comprises an upper grinding disc, a lower grinding disc, a driven gear, a driving gear and a driving motor, the material conveying mechanism comprises a material containing tray, a screening branched chain, a material conveying pipe and a material guiding ring. According to the grinding and dispersing machine, the graphene is ground in a multi-stage grinding mode, and the sizes of graphene which meet the standard and do not meet the standard can be separated in advance before the subsequent grinding stage, so that the purposeof improving the subsequent grinding efficiency and the grinding quality is achieved.