A displacement measurement method for microcantilevers based on integrated dual gratings and a CCD image measurement system were presented. The displacement detection range was extended by using two gratings with a phase shift about π/2. The sensor chips were fabricated by surface sacrificial process. Grooves with the depth about 1/8 of the incident laser wavelength were etched on the glass substrate and two adjacent gratings patterned inside and outside of the groove and the reflective undersurface of a cantilever formed two phase sensitive integrated gratings, respectively. The integrated grating units formed an image on the CCD sensing surface through the 1st order diffraction light, and the gray value change of the light spot was related to the displacement change of the corresponding cantilever. Experimental results show that although the phase difference between the gratings deviates from π/2 caused by the depth errors of the etched grooves, the integrated dual gratings extend the range of displacement detection to multi periods. The insensitive areas at peaks and valleys for sinusoidal variation signal of interferometric displacement detection method are avoided by using alternately intensity signals from the two gratings. In the experiment, the measured displacement change of the cantilever is 650 nm.