Energy-saving petroleum drilling machine lifting system

The invention discloses an energy-saving petroleum drilling machine lifting system which comprises an engine unit, a gearbox, a roller, a roller brake, a traveling block hook and a derrick and further comprises a chain transmission, an epicyclic gear train, an ordinary gear train, a motor unit, an inverter and a lithium battery pack. The power of the engine unit is about 1/4 of that of a conventional petroleum drilling machine, the engine unit works under rated power during auxiliary operation and when a drill column is lifted, and the problem of power waste caused by the fact that a high-power engine of the conventional petroleum drilling machine works under extremely low power for most time is solved. When the drill column is lifted, three force gear modes are configured along with the change of the weight of the drill column, so that energy is fully utilized and saved. When the drill column is lowered, gravitational potential energy of the drill column is converted into electric energy in the lithium batte