The invention discloses a method for obtaining the quenching process heat transfer coefficient of an aluminum alloy component under the three-dimensional heat transfer condition based on a finite element method, and relates to the technology of obtaining the heat transfer coefficient under the three-dimensional heat transfer condition. The method aims to solve the problem that the heat transfer coefficient obtained under the one-dimensional heat transfer condition does not agree with the heat transfer coefficient of the actual aluminum alloy component under the three-dimensional heat transfer condition, and thus the obtained heat transfer coefficient is inaccurate. The method includes the steps that a three-dimensional heat conduction differential equation under a rectangular coordinate system is established; on the basis of the finite element computing method, the aluminum alloy component is subjected to finite element mesh generation, and the temperature field corresponding to a certain moment of time is calculated; whether the test temperature and the calculating temperature of a test point meet a convergence condition or not is judged; if yes, the method is ended; if not, a novel heat transfer coefficient is obtained through optimization by means of a genetic algorithm; a novel temperature field is calculated according to the novel heat exchange coefficient, and whether the test temperatures and the calculating temperatures of N test points meet the convergence condition or not is continuously judged. The method can be used for obtaining the heat transfer coefficient under the three-dimensional heat transfer condition.