The invention relates to a high-power helical planetary transmission. The high-power helical planetary transmission comprises a driving shaft, planetary gears and a gear ring. A sun wheel is arrangedat the right end of the driving shaft. The multiple planetary gears are evenly distributed at the periphery of the sun wheel. The planetary gears are installed on a planet carrier through a planet wheel bearing. The multiple planetary gears are sleeved with the gear ring. The right end of the gear ring is installed on a gear ring carrier. The planetary gears are helical gears and are enabled to beengaged with the sun wheel and the gear ring respectively. A left inner thrust collar and a right inner thrust collar are correspondingly arranged on the two sides of the planetary gears. The left inner thrust collar and the right inner thrust collar are used for transmitting axial force generated when the planetary gears rotate to the driving shaft. The high-power helical planetary transmissionhas the advantages of being simple in structure, small in size, long in service life, high in power and high in reliability, can completely meet the requirements of heavy vehicles on high-power transmissions, and is beneficial for reducing vibration and noise, and upgrading the comfort level of driving.