Crane landing leg supporting device and crane

The invention relates to a crane landing leg supporting device and a crane, the crane landing leg supporting device comprises a fixed supporting component (2) and a movable supporting component (3), the fixed supporting component (2) comprises a first plate-shaped component (21) and a slideway (25) which is arranged on the plate-shaped component (21) and extends along a first direction perpendicular to the thickness direction of the plate-shaped component (21); the movable supporting component (3) is arranged in the sliding way (25) in a sliding mode in the first direction so as to extend out of the fixed supporting component (2) or retract into the fixed supporting component (2), and the movable supporting component (3) is arranged in the sliding way (25) of the fixed supporting component (2) in a telescopic mode. Therefore, the supporting leg supporting device can change the length of the movable supporting part (3) extending out of the fixed supporting part (2) according to different working sites, and the