In order to improve the performance of the inversion algorithm for travel time tomography, a simple iterative algorithm based on the precise integration method was used. The improved algorithm could be considered a simple iterative process. The precise integration method was used to solve the inverse matrix to ensure convergence and obtain the true solution to the equation at a higher speed of iteration. The checkerboard model recovery test and real data inversion results show that the calculation process of the improved algorithm is simple, and the algorithm can obtain the velocity profile with higher resolution and fewer iterations. Compared with some commonly used methods, this algorithm has higher image resolution and greater iteration efficiency.