Digital holographic microscopy (DHM) is proposed for the three-dimensional (3D) profile measurement of the micro-optical components, which is characterized by its non-invasion, non-contact, high-speed, and full-wave field scheme. Firstly, the configuration of lensless Fourier-transform DHM is designed and built. The complex amplitude of the full-wave field is reconstructed by a single inverse fast Fourier transform only. The phase aberration is corrected by the two-step phase subtraction method, and the unwrapped phase information is extracted by using the least-squares phase-unwrapping algorithm. Then the profile information of the sample can be obtained. In the experiments, the profile of the micro-lens arrays is measured by the proposed configuration, and the results show that the caliber and relief depth are 1.595 mm and 2.424 μm respectively. These are in good agreement with the results given by the white-light interferometer. It demonstrates that the lensless Fourier-transform DHM is feasible and effective for the 3D profile measurement of the micro-optical components.