Desk and chair with waist support assembly

The desk and chair comprises a backrest arranged at one end of a chair and armrests arranged on the two sides of the chair, a waist protection air bag is arranged on the side, corresponding to the waist of the human body, of the backrest, an air box is arranged on the other side of the backrest, an air storage cavity is formed in the air box, and the waist protection air bag is communicated with the air storage cavity through an elastic connecting pipe. An electric push rod is installed at the end, away from the waist protection air bag, in the air storage cavity, a piston type piston push plate is fixedly connected to one end of a telescopic rod of the electric push rod, and supporting springs are fixedly connected to the upper end and the lower end between the waist protection air bag and the backrest respectively. The arc shape of the waist protection air bag and the inclination angles of the upper end and the lower end of the waist protection air bag can be adjusted according to the requirements of differ