A method for preparing hydrogen-rich gas from solid organics, comprising: heating the solid organic raw materials in a pyrolysis reaction device to allow pyrolysis occurs; and performing gasification of a gaseous product and steam in a moving bed gasification reaction device to generate hydrogen-rich gas, in which the gaseous product is generated from pyrolysis; wherein the pyrolysis reaction device is in parallel with the moving bed gasification reaction device; by passing through a solid heat carrier grading-dedusting device, the solid heat carrier is divided into two parts which are fed into the pyrolysis reaction device and moving bed gasification reaction device respectively, and when leaving the pyrolysis reaction device and moving bed gasification reaction device, both the two parts of solid heat carrier are fed into a riser and combustion reactor to be heated and raised, and then passed into the solid heat carrier grading-dedusting device again to be divided into two parts, and these two parts are then respectively fed into the pyrolysis reaction device and the moving bed gasification reaction device again to create a cycle; wherein the part of the solid heat carrier that is fed into the pyrolysis reaction device is used as a heating medium for pyrolysis, and the other part of the solid heat carrier that is fed into the moving bed gasification reaction device is used as a heating medium for the gasification; and wherein the solid heat carrier grading-dedusting device divides the solid heat carrier into two parts based on the average particle size, wherein the part with smaller average particle size is fed into the pyrolysis reaction device, and the other part with larger average particle size is fed into the moving bed gasification reaction device. heating the solid organic raw materials in a pyrolysis reaction device to allow pyrolysis occurs; and performing gasification of a gaseous product and steam in a moving bed gasification reaction device to generate hydrogen-rich gas, in which the gaseous product is generated from pyrolysis; wherein the pyrolysis reaction device is in parallel with the moving bed gasification reaction device; by passing through a solid heat carrier grading-dedusting device, the solid heat carrier is divided into two parts which are fed into the pyrolysis reaction device and moving bed gasification reaction device respectively, and when leaving the pyrolysis reaction device and moving bed gasification reaction device, both the two parts of solid heat carrier are fed into a riser and combustion reactor to be heated and raised, and then passed into the solid heat carrier grading-dedusting device again to be divided into two parts, and these two parts are then respectively fed into the pyrolysis reaction device and the moving bed gasification reaction device again to create a cycle; wherein the part of the solid heat carrier that is fed into the pyrolysis reaction device is used as a heating medium for pyrolysis, and the other part of the solid heat carrier that is fed into the moving bed gasification reaction device is used as a heating medium for the gasification; and wherein the solid heat carrier grading-dedusting device divides the solid heat carrier into two parts based on the average particle size, wherein the part with smaller average particle size is fed into the pyrolysis reaction device, and the other part with larger average particle size is fed into the moving bed gasification reaction device.