The utility model discloses a drainage structures at bottom of tunnel, fill the longitudinal drainage channel below the top including setting up at the left and right both sides in tunnel inverted arch, longitudinal drainage channel in buried the longitudinal drainage pipe underground, the bottom in tunnel is equipped with a plurality of hoop drain pipes, each hoop drain pipe all through three tee bend respectively with the one end intercommunication of three radial drain pipe, the other end of three radial drain pipe all links to each other with central ditch, each three -way third end all communicates with a longitudinal drainage pipe, longitudinal drainage channel pass through the drain pipe intercommunication with the lateral sulcus that sets up in the left and right both sides in tunnel. The utility model discloses simple structure, each some tunnel bottom drainage pipe arranges position, structure and size reasonable in design, the utility model discloses be under construction convenient, construction speed is rapid, the utility model discloses a pressure -relief is good, can be less effectively tunnel bottom water evil problem give the risk that railway operation safety brought.