The phase unwrapping algorithms are divided into the path-dependent type and the path-independent type, and can be widely used in the field of optical measurements. An improved path-independent phase unwrapping algorithm based on total-variation minimum denoising is proposed to wipe off the remained noise in the residual phase. Firstly, the phase gradient is determined from the wrapped phase map and subsequently denoised by the total-variation minimization based method. Thus, an approximate phase unwrapped map can be obtained by integrating the denoised phase gradient, and the residual phase map is denoised. The final phase unwrapped map is subsequently determined by adding the first few modes of the unwrapped phase. Error values of unwrapped phase before and after denoising are compared with the original phase by simulations and experiments. The results show that the values of peak-valley and root-mean-square of unwrapped phase with residual phase denoised are lower than those of unwrapped phase with residual phase not denoised.