The static waveband grooming algorithm is studied. Waveband switching can effectively decrease the ports of wavelength switching. But the granularity of waveband is difficult to be set when it is constant. When the waveband granularity is large, the switching ports can be decreased while the waveband utilization is low. When the waveband granularity is small, the waveband utilization is high while the switching ports can be increased. To solve this problem, a multi-granularity waveband scheme is proposed. The static traffic grooming is similar to multicast routing in some degree. So the multicast tree is used to solve the waveband grooming problem. In order to decrease the connection ports between the waveband switching plane and wavelength switching plane, the same destination grooming scheme is adopted. A new waveband auxiliary graph is proposed for this grooming scheme. The simulation result shows that the scheme proposed can decrease the waveband switching ports and improve the waveband utilization ratio effectively.