We propose a novel digital holographic microscopy (DHM) by integrating surface plasmon holographic microscopy (SPHM) with reflection DHM based on the angular and polarization multiplexing techniques. Taking advantages of the high sensitivity of surface plasmon resonance (SPR) and the high reflectivity of gold film, the tiny variations of specimen's refractive index (RI) can be measured by using SPHM, and meanwhile, the thickness changes of the specimen can be determined by means of reflection DHM. We experimentally monitor the volatilization process of an alcohol-water mixture droplet to verify the validity of the integrated DHM. The proposed microscopy is very promising in the objective-coupling SPR microscopy for multi-information measurements of diverse specimens with low-contrast RI distributions (biomolecules, nanofluids, etc.) in a dynamic and nondestructive way.