The invention relates to the communication field and provides a method and a device for requesting a computing path in multiple-domain networks. The method for requesting a computing path in multiple-domain networks, which is provided by the embodiment of the invention, comprises the following steps: receiving a path computing request message, wherein the path computing request message carries PCE information and domain information of a path computing unit, and the domain information corresponds to the PCE information; acquiring the information of a boundary route device according to the domain information; and implementing PCE-based backward recursive computation by using the information of the boundary route device. By using the method and the device provided by the embodiment of the invention, the path computing request message received by PCE carries the PCE information and the domain information, so the information of the boundary route device, which is needed for BRPC computation, can be acquired, and BRPC can be used for realizing the computation of cross-domain paths.