The invention discloses a two-freedom-degree hydraulic mechanical arm joint adopting a cross joint for connection. The two-freedom-degree hydraulic mechanical arm joint comprises a right oil cylinderassembly, a left oil cylinder assembly, a frame type cross shaft, a supporting frame and an arm body; the cross shaft is provided with a vertical rotation center line and two horizontal rotation center lines, one horizontal rotation center line is connected with a left piston rod of the left oil cylinder assembly through a rotation pair, the other horizontal rotation center line and the arm body form a rotation pair, and the vertical rotation center line and the support frame form a rotation pair; a right piston rod of the right oil cylinder assembly is installed on the supporting frame through a first hinge cross joint assembly; and a left oil cylinder of the left oil cylinder assembly is connected with the arm body through a rotating pair, and a right oil cylinder of the right oil cylinder assembly is installed on the arm body through the cross joint. The hydraulic mechanical arm joint adopts the cross shaft structure, the front end of the mechanical arm is hydraulically driven to realize two-freedom-degree rotation around the two shafts at the same time, flexible action can be realized under a heavy-load working condition, and the hydraulic mechanical arm joint has the advantages of a large force-weight ratio, flexible action and stability.