The disclosure discloses a sensing aiding method for cognitive radio. The method includes the following steps. a high level node transmits configuration information to a base station; the base station combines with a subordinate node of the base station to perform frequency spectrum sensing measurement, in which the subordinate node has sensing capability, and feeds back a result of the sensing measurement to the high level node; and the high level node formulates a corresponding WS allocation policy according to the received result of the sensing measurement. The disclosure also discloses a system. By the method and the system of the disclosure, the high level node transmits the configuration information to the base station; the base station performs the spectrum sensing measurement in combination with the subordinate node having the sensing capability of the base station in a designated frequency band and feeds the result of the sensing measurement back to the high level node; and the high level node formulates the corresponding WS allocation policy according to the result of the sensing measurement. Available white band resources are acquired; the probability of base station configuration failure is reduced, and the overhead caused by configuration failures is reduced.