In holographic reconstruction, the two-order and twin image noise produced by the phase-conjugate wave arising from the symmetry of the complex field, will affect the accuracy and the image quality of the reconstructed image. The acquisition of the holographic focus distance parameter for judging the best focal plane of object is also the key to holographic imaging. In this work, a numerical focusing imaging algorithm based on compressive sensing is proposed. By choosing a stack of reconstructed images in the axial direction with fixed interval, every image is processed by the total variation regularization. These images are used to calculate and construct the focus curve of the digital holography according to the focus metrics such as the tamura coefficient and the absolute gradient operator. Then the best focus plane is evaluated. The proposed method suppresses the noise of in-line digital reconstruction, improves the axial accuracy of reconstructing, and realizes a larger range of high-resolution imaging around the focus plane.