Marine hydraulic telescopic folding crane

The utility model discloses a marine hydraulic telescopic folding crane. The marine hydraulic telescopic folding crane is characterized in that a rotating support (4) is connected above the base (1), an oil pump unit (2) is arranged in the base (1), a rotating device (5) is arranged in the rotating support (4), one end of an amplitude modulating arm (9) is hinged above the rotating support (4), the other end of the amplitude modulating arm (9) is hinged with a basic jib (11), a hoisting winch (6) and an amplitude modulating oil cylinder (19) are arranged on the rotating support (4), the amplitude modulating oil cylinder (19) is connected with the amplitude modulating arm (9), the amplitude modulating arm (9) is provided with a folding oil cylinder (20), the folding oil cylinder (20) is connected with the basic jib (11), a No. 1 telescopic arm (15) and a telescopic oil cylinder (13) are arranged in the basic jib (11), the telescopic oil cylinder (13) is connected with the No. 1 telescopic arm (15), and the oil