Engineering reliability analysis method for solving low failure probability

The invention discloses an engineering reliability analysis method for solving a low failure probability. The method comprises the following steps: determining a performance function and a distance index; decomposing the hypersphere space to obtain sub-domains which are not overlapped with each other, and adaptively determining the number of division layers of the sub-domains based on a first convergence condition; on the basis of a second convergence condition, adaptively adding sample points in the key area which contributes to the failure probability; and outputting the failure probability of the engineering structure meeting the second convergence condition. According to the method, multi-failure domain information of an engineering structure can be prevented from being obtained in advance, meanwhile, a large amount of sampling can be performed in a sample space in a manner of focusing on a key region which contributes to a failure probability, so that excessive invalid sample points generated in a non-fa