At the special Strehl ratio( the ratio of the maximum intensity of the central core of the superresolving pattern to the Airy pattern) 3-zone amplitude-type pupil filters are designed by nonlinear programming and goal programming,which can let the imaging system resolutions of transverse,axial and 3-D reach the maximum. Some superresolution optimization design models and examples are presented with figures testification. To suppress the sidelobe intensity which is concomitant with the increase of the resolutions, these filters are used in confocal scanning microscopic system, as a result, higher signal-to-noise and good image contrasts are achieved. The strategie can also be applied to designing phase-only or more than 3-zone amplitude-type superresolution filters, which gives some references for the design of superresolution filters.