A patient interface for continuous positive airway pressure (CPAP) therapy, comprising: a cushion assembly , comprising: a shield , having an opening structured on a first end of the cushion assembly and a ring structure projecting from the opening in a direction towards the first end of the cushion assembly ; a cylindrical wall , provided to the opening by a plurality of support structures and formed as concentric with the opening, the cylindrical wall projecting in a manner of having different diameters in two opposite directions along an axis of the opening; and a sealing assembly , provided to the shield of the cushion assembly and together form a breathing chamber, the sealing assembly adapted to seal a face of a patient; a headgear assembly , including a plurality of straps for fixing the patient interface in use; an elbow assembly , adapted to be in fluid communication with the cushion assembly, so as to deliver an air flow to airways of the patient when in use; a connecting ring structure , having one end connected to the cushion assembly and one other end non-detachably connected to the elbow assembly ; and a headgear secure assembly , adapted to engage with the connecting ring structure , the headgear secure assembly including a plurality of slots adapted to attach to the corresponding straps in use, wherein the headgear secure assembly is not provided with a forehead support. a cushion assembly , comprising: a shield , having an opening structured on a first end of the cushion assembly and a ring structure projecting from the opening in a direction towards the first end of the cushion assembly ; a cylindrical wall , provided to the opening by a plurality of support structures and formed as concentric with the opening, the cylindrical wall projecting in a manner of having different diameters in two opposite directions along an axis of the opening; and a sealing assembly , provided to the shield of the cushion assembly and together form a breathing chamber, the sealing assembly adapted to seal a face of a patient; a shield , having an opening structured on a first end of the cushion assembly and a ring structure projecting from the opening in a direction towards the first end of the cushion assembly ; a cylindrical wall , provided to the opening by a plurality of support structures and formed as concentric with the opening, the cylindrical wall projecting in a manner of having different diameters in two opposite directions along an axis of the opening; and a sealing assembly , provided to the shield of the cushion assembly and together form a breathing chamber, the sealing assembly adapted to seal a face of a patient; a headgear assembly , including a plurality of straps for fixing the patient interface in use; an elbow assembly , adapted to be in fluid communication with the cushion assembly, so as to deliver an air flow to airways of the patient when in use; a connecting ring structure , having one end connected to the cushion assembly and one other end non-detachably connected to the elbow assembly ; and a headgear secure assembly , adapted to engage with the connecting ring structure , the headgear secure assembly including a plurality of slots adapted to attach to the corresponding straps in use, wherein the headgear secure assembly is not provided with a forehead support. <EOS>