Abstract: To solve the problems in quantitative phase contrast imaging such as the alternate increase and decrease between multi-peak phase distribution and wrapping phase distribution and the existence of multiple extremum points of the wrapping phase when the original phase exceeds the period π, a phase-unwrapping algorithm based on self-adaptive threshold reversal (SATR) is proposed. The algorithm realizes real phase reconstruction in quantitative phase contrast imaging. The realization of the principle of phase contrast imaging and the self-adaptive threshold reversal algorithm is analyzed, and the feasibility and accuracy of the method are proved through simulation verification calculation and comparison with Least-Square phase unwrapping algorithm (LS), Least-Square algorithm based on Lateral sheering interferometry (LSBLS) and Four-Direction Least-Square phase unwrapping algorithm based on Lateral shearing interferometry (FLSBLS). The algorithm improves the precision of phase unwrapping to some extent and provides a new idea for phase unwrapping under strong interference, demand for high precision and a large amount of calculation.