The present invention discloses a method and apparatus for querying a nondeterministic graph, which are used to implement quick query of a nondeterministic graph, reduce query complexity, and improve query efficiency. The method comprises receiving a query instruction, where the query instruction is used to query a nondeterministic graph for data that satisfies a query condition; determining two vertices in the nondeterministic graph according to the query instruction; determining all possible paths that use one vertex in the two vertices as a start point and the other vertex as an end point; calculate a probability of a first event or a second event corresponding to each of the paths; and obtaining, according to the probability of the first event or the probability of the second event, a query result corresponding to the query instruction.