The invention relates to the field of active coke preparation, and especially relates to a preparation system and a preparation method of active coke. The preparation method for simplifying the active coke improves the application values of byproducts to maximize the resource utilization rate of coal. The complexity of present preparation technologies of active coke is overcome, and the obtained byproducts have low defects. The preparation system of the active coke provided in the embodiment of the invention comprises a gasification furnace, and the gasification furnace includes a reaction chamber and a chilling chamber arranged below the reaction chamber; the reaction chamber is used for a coal gasification reaction of coal powder and a hydrogen-containing gas injected to the reaction chamber at a preset temperature under a preset pressure; and a chilling substance nozzle is arranged in the chilling chamber, and the chilling substance nozzle is used for injecting a chilling substance to chill the product of the coal gasification reaction in order to obtain the active coke.