The proposal of memristor theory has greatly promoted the development of chaotic systems, enriching the dynamics of chaotic circuits. The operational amplifier becomes an important part of the memory circuit model due to its powerful signal processing capacity. In this paper, a simplified operational amplifier based on low power differential pair is constructed and this operational amplifier reduces the number of required transistors to two. Then, the simulation equivalent circuit model and hardware experimental circuit of a new type of second-order magnetron memristor are created. The results show that with the increase of the excitation signal frequency, the side lobe area of the "8" decreases; with the increase of the excitation signal amplitude, the side lobe area of the "8" increases. The results of circuit simulation and hardware circuit experiments have verified the validity of the new model of magnetron memristor and the accuracy of the design method.