We can quickly and properly acquire the traveltime and ray path of first-break through forward calculation on the near-surface model by using linear traveltime interpolation ray tracing. As the first-breaks calculated by this method not only contain refraction but also other parameters, the problem of shielding layer in shallow refraction exploration caused by a low velocity can be satisfactorily solved. Moreover, based on gridding division and linear interpolation, this method can trace first-breaks in any complex media and can make the traced ray path approach the real condition, thus avoiding the direct connection of web nodes to form ray paths which causes a bigger traveltime value due to the serious bending of the ray path. Several other methods are compared with the LTI method in this paper, and the result shows that the LTI method is more precise and stable than other methods in calculating traveltime and ray path of first-breaks. It is thus concluded that LTI is an effective ray tracing method.