Comfortable chair suitable for multiple usage postures

A comfortable chair suitable for multiple usage postures, comprising:

• a chair seat and chair legs, a pneumatic rod being arranged between the chair seat and the chair legs, and the chair seat and the chair legs being connected through the pneumatic rod;
• two chair armrests symmetrically arranged on two sides of the chair seat;
• a chair backrest, a backrest frame being arranged on a side, away from the chair seat, of the chair backrest, a desk board being arranged in the backrest frame and connected with the backrest frame in an overturnable manner, a chair support being arranged between the chair backrest and the chair seat, one end of the chair support being arranged in the backrest frame, and the other end being connected with the chair seat;
• and
• at least one desk board adjustment mechanism arranged on a surface of the backrest frame, the desk board adjustment mechanism comprising a strip-shaped chute, a sliding stop block and an overturning shaft, the sliding stop block being in sliding fit with the strip-shaped chute, a wall of the strip-shaped chute being provided with at least one first limiting slot, one side of the sliding stop block being provided with a limiting protrusion which is able to be embedded into the first limiting slot, and two ends of the overturning shaft being respectively connected with the sliding stop block and the desk board in an overturnable manner;
• wherein
• the overturning of the desk board drives the overturning shaft, so that the sliding stop block slides in the strip-shaped chute, and when the limiting protrusion is snapped into the limiting slot, the angle of the desk board is fixed.