The invention provides an acid reaction tank for preparing kerogen. The acid reaction tank comprises a tank body, an end cover, a gas stirring device and a gas discharging device, wherein the end cover can be connected with the tank body in a sealed mode, one end of the gas stirring device is inserted into the tank body for mixing acid liquid and a rock sample, and the gas discharging device is used for discharging gas in the tank body. The acid reaction tank has the advantages that the end cover and the tank body are sealed, liquid and gas are prevented from leakage, and environment is protected; manual stirring is replaced by gas mixing, the working efficiency is improved, labor is saved, and health and safety of operators are guaranteed; a teflon material is used for making the tank body and the end cover, corrosion resistance and high-temperature resistance are achieved, the acid reaction tank can be suitable for a kerogen separation test of the long time, and the testing effect isguaranteed.