The present disclosure relates to a method and a system for measuring train wheelbase. The method includes: judging whether train wheels are passing by at least two non-contact sensors at present according to sensing data from the at least two non-contact sensors arranged on an outer side of a train track and arranged at intervals along the train track; in response to determination that train wheels are passing by the at least two non-contact sensors at present, calculating a moving speed of the train wheels according to the sensing data from the at least two non-contact sensors, and calculating a first time interval of adjacent train wheels passing by a same non-contact sensor of the at least two non-contact sensors; and calculating a wheelbase of the adjacent train wheels based on the moving speed and the first time interval. By adoption of the embodiment of the present disclosure, the adaptability of train wheelbase measurement can be improved.