The invention discloses a high-reliability multifunctional axle counter system and method adopting a laser coorelation instrument. The axle counter system comprises an existing axle counter and the extension laser coorelation instrument, and has good realizability. The extension laser coorelation instrument with a laser coorelation detector serving as the core comprises a laser emission end, a laser receiving end, a CC2500 communication module and a main control module. The axle counter is additionally provided with the laser coorelation instrument for assisting in axle counting, and the defects that an existing electromagnetic axle counter is prone to electromagnetic interference and the performance becomes poor during low-speed travelling are overcome; the communication module downloads the number of axles of related trains of a train automatic monitoring system ATS, the axle counter counts the number of the axles, the laser coorelation instrument assists in counting the number of the axles, and the numbers of the axles are compared, the reliability of the axle counter is improved; and the laser coorelation instrument is applied, so that the intrusion line checking, external object interference suppressing and fault diagnosis functions are extended.