Based on analyzing the physical mechanism of reliable acoustic path, and combining RAP and time reversal positioning technology, positioning problem of horizontal hydrophone array based on RAP was researched. Simulation results under the condition of Munk sound speed profile showed positioning validity of horizontal hydrophone array based on RAP. Improving the numbers of sensor and distance between sensors could enhance timereversal energy focus effect. On the same condition horizontal line array (HLA) more elements are required compared with vertical line array (VLA).