The invention discloses a method and a device for preparing low carbon alkene from an oxygen-containing compound. The method and the device solve the problem in the prior art that the flexible control of a reactor temperature can not be realized. The technical proposal adopted in the invention is as follows: a reactor product flow (4) passes through a heat exchanger (5) to exchange heat with the oxygen-containing compound material (1), and then enters a quenching system; after heat exchange, the oxygen-containing compound material (1) enters a cooling heat exchanger (8) to adjust temperature,and then enters a reactor (2); a heat-taking cooler is arranged inside the reactor (2) to take the surplus reaction heat out of the reactor (2). By using the method, the flexible control of the reaction temperature in the reactor can be realized, and the attrition rate of a catalyzer in a heat-taking device is largely reduced.