In order to adjust and detect micro-nano metasurfaces accurately and efficiently, the problem of coupling scattering between a grid micro-nano metasurface and buried micro-defects is studied based on the multi-resolution time domain (MRTD) method. The concept of multi-resolution is introduced, and the coupling scattering model is established from the Maxwell equation. The scattering field is derived and compared with the finite difference time domain (FDTD) method. The correctness of MRTD is verified and its advantages are analyzed. According to the field distribution of the grid metasurface containing micro-defects, the necessity of studying the influence of various parameters of defects on the optical system of metamaterials is given. Then, the effects of the parameters such as defect size, buried depth, and relative orientation on the coupling scattering characteristics are analyzed numerically. The results provide technical supports for the fields and directions of functional surface design, ultrasensitive detection, scattering peak orientation, and frequency selection.