Fork leveling system and method, and telescopic boom forklift

A fork leveling system, comprising:

• an active leveling oil cylinder;
• a passive leveling oil cylinder;
• an electric control oil supplement valve;
• and
• an electric control reversing valve;
• wherein
• a rodless cavity of the active leveling oil cylinder is communicated with a rodless cavity of the passive leveling oil cylinder, and a rod cavity of the active leveling oil cylinder is communicated with a rod cavity of the passive leveling oil cylinder;
• and
• an oil inlet of the electric control oil supplement valve is connected to an oil pump, and an oil outlet of the electric control oil supplement valve is connected to the rodless cavity of the active leveling oil cylinder and the rod cavity of the active leveling oil cylinder,
• wherein when the fork leveling system is in a leveling state, the electric control oil supplement valve is controlled to be open, and the oil pump is controlled to supply oil to the rodless cavity and the rod cavity of the active leveling oil cylinder;
• and
• the electric control reversing valve comprises an oil inlet, a first working oil port, a second working oil port and an oil return port;
• the oil inlet of the electric control reversing valve is connected to the oil pump, the oil return port of the electric control reversing valve is connected to the oil tank, the first working oil port of the electric control reversing valve is connected to the rodless cavity of the active leveling oil cylinder through a first pipeline, and the second working oil port of the electric control reversing valve is connected to the rod cavity of the active leveling oil cylinder through a second pipeline.