The utility model relates to a shaped adjustable stair for foundation pit construction. The staircase is a solid integrated shaped product composed of a staircase base body, a security handrail, an upper end fixing component, a pit bottom fixing component, a continuous connecting component, a traction supporting component and a step supporting component. The upper end fixing component and the pitbottom fixing component can be used for limiting, fixing, dismounting, shifting and recycling as required; the effective working length is extended by means of the continuous connecting component; theuse requirements of foundation pit construction sites with different depths can be met; structure is scientific and reasonable, conveniently-arranged time-saving and labor-saving device, work safetyand reliability, the defects that in the prior art, labor and time are wasted, waste materials are wasted, the arrangement cost is high, potential safety hazards exist, and the resource waste phenomenon is serious when foundation pit construction stairs are frequently erected and disassembled are overcome. Civilized management, safe production, efficient construction, construction cost reduction and other economic, practical and environment-friendly positive technical effects are brought to the construction industry, and extremely high practicability is achieved.