Based on a microdisk resonator device with a diameter of 7.2 μm, the symmetric and asymmetric defects were introduced. By using the finite difference time domain method , the influences of the positions and dimensions of the defects on the resonant modes of microdisks were analyzed. The results show that with the increase of the radius of defects resonance modes firstly move towards shorter wavelength and then get suppressed progressively. Furthermore, a microdisk was introduced in two kinds of defects to form embedded-type dual microdisk resonators. After the optimization of the relative positions and dimensions, the single-mode resonance is realized at 1 128 nm and 1 109 nm. This device overcomes the drawbacks of single microdisk and simplifies the resonance mode, it can be applied in wider interest fields.