Abstract: Through the improvement to the LTI track formula (linear travel-time interpolation) and global scanning method, a HLTI based on higher order weighting and maze algorithm has been advanced. By means of improving LTI track formula via bringing in Taylor higher order weighted item, this new algorithm reduces the accumulative error caused by linear condition hypothesis, improves the accuracy of ray-tracing, and thus solves the invalidation problem come about by the complex-value solution of LTI track formula. Besides, by taking advantage of the maze algorithm principle to optimize the global scanning method, the problem of the traditional scanning method which is incapable of backward and vertical tracing has been solved. The simulation experiment results indicate that the new HLTI has higher ray-tracing accuracy and better image quality than the traditional LTI.