The invention discloses a continuously-variable transmission for a mechanical direct-drive hydraulic double-control tracked vehicle. According to the
continuously variable transmission, a power input portion inputs power to an advance and retreat gear deceleration portion, the advance and retreat gear deceleration portion transmits power to a differential planetary transmission stepless speed change portion through an intermediate
power transmission portion, then, the differential planetary transmission stepless speed change portion outputs the power to a drive transition deceleration transmission portion, and finally the power is transmitted to a left side
caterpillar band drive portion and a right side
caterpillar band drive portion, wherein an advance and retreat gear control portion is used for gear switching of the advance and retreat gear deceleration portion. Double self-locking type hydraulic motors are arranged in the differential planetary transmission stepless speed change portion, so that mechanical direct drive, hydraulic stepless speed regulation and
steering control are achieved. When the double self-locking type hydraulic motors are in the same working state, the tracked vehicle achieves mechanical direct drive and hydraulic stepless speed regulation drive; when the double self-locking type hydraulic motors are not in the same working state, rotating speed difference happens between left side
caterpillar band output wheels and right side caterpillar band output wheels,
hydraulic control steering is achieved, transmission and steering of the tracked vehicle are integrated, operation is easy and convenient to perform, and the tracked vehicle is easy to drive.