摘要Phase contrast imaging technique has been improved promptly in recent years. Among these techniques in-line phase-contrast imaging is widely used. Various algorithms for in-line phase retrieval have been proposed so far such as TIE (transport of intensity equation), CTF (contrast transfer function), first born-approximations, GSF (Gerchberg-Saxton-Fienup), etc. Bronnikov's algorithm(BA) is a type of linear algorithm that is simple and efficient. But it can only be used without absorption situations. In this paper, an improved algorithm based on BA was presented. The approach adds Δφ(x,y) to the phase mapφb (x,y) retrieved by BA to make the reconstructed phase map more precise. Further, the approach was evaluated on simulated images and confirmed to be accurate at higher absorption rates.