The phase retrieval algorithm has always had some questions such as low precision, long convergence time and even stagnation. Based on the transport of intension equation (TIE)-Gerchberg-Saxton (GS) iteration hybrid algorithm improves the precision of phase retrieval, and gradient algorithm increases the iteration step and accelerates the convergence speed. This paper compares and analyses the GS-TIE algorithm and amplitude addition gradient algorithm retrieval effect from the perspective of simulation and experiment for GS-TIE algorithm and amplitude addition gradient algorithm. Based on the 2D images simulation for the comparison of two phase retrieval algorithms, it proves that the convergence speed of the algorithm is three times that of GS-TIE iteration algorithm, the accuracy of the algorithm is better than GS-TIE iteration algorithm, and the accuracy is ten times better than GS-TIE iteration algorithm. The experimental results show that GS-TIE algorithm retrieval phase is clearly visible, the contour is obvious, and it is excessively uniform at the edge, while the amplitude addition gradient algorithm is relatively fuzzy, and it is excessively uneven at the edge of the contour and has a large suspension.