The utility model provides an
office chair backrest structure with an adjustable
waist support position, which relates to the technical field of office chairs and comprises a main body mechanism, a plurality of positioning mechanisms, a control mechanism and a
waist support mechanism. Before use, people adjust the height of the
waist support mechanism through the positioning mechanism, then adjust the
sitting posture to make the waist contact with the waist support mechanism, then press a button to start an air
feed pump, and air is fed into a control valve shell through an air pipeline, pushes a
piston to rise and then enters an air bag, so that the air bag is expanded and accurately fits the waist curve of a user; local compression or suspension of the waist is avoided, fatigue caused by long-time sitting is effectively relieved, the burden of intervertebral discs and muscles is reduced, occupational diseases such as
lumbar disc herniation and
lumbar muscle strain are prevented, when the air bag is tightly attached to the waist and cannot continue to expand, air accumulated in the control valve shell pushes the
piston to further ascend, contacts make contact to form a circuit, and the air bag is prevented from being blocked. The air supply pump is automatically closed, excessive
extrusion on the waist is prevented, and errors caused by manual operation are effectively avoided through automatic adjustment.