The invention provides a method and system for measuring a dual superposition orbital angular momentum (OAM) of a radio frequency signal. The method includes the following steps: collecting phase information of the radio frequency signal, and obtaining a ring phase function; and calculating two OAM states of the radio frequency signal according to the ring phase function. According to the technical scheme provided by the invention, a rotating platform can drive a receiving antenna to rotate around a rotating shaft, the receiving antenna collects the phase information of the entire receiving ring, and thus a processor obtains the ring phase function according to the phase information and calculates the two OAM states of the radio frequency signal according to the ring phase function, and the measurement of the dual superposition OAM states of the radio frequency signal can be achieved.