Triangle track walking mechanism and mountain half track tractor, related to the field of agricultural machinery. The triangle track walking mechanism includes a driving wheel, a bracket, a track, a supporting device, a guiding device, and a tensioning device. The driving wheel is set at one end of the bracket, and the supporting device, a guiding device, and a tensioning device are all set at one end of the bracket away from the driving wheel. The guiding device and tensioning device are set on both sides of the bracket, and the driving wheel, supporting device, guiding device, and tensioning device are all coordinated with the same side of the track. The triangle track walking mechanism and mountain half track tractor provided by this utility model are selectively connected to the vehicle body through the triangle track walking mechanism, improving the working efficiency of the mountain half track tractor