A conductive yarn pressure sensor is proposed. The pressure sensor may include a porous fiber layer having predetermined cavities formed therein. The pressure sensor may also include a first sensing electrode made of a first conductive yarn formed on one surface of the porous fiber layer, and a second sensing electrode made of a second conductive yarn formed on the other surface of the porous fiber layer. The first sensing electrode or the second sensing electrode may be provided so as to be in contact with each other in the cavities of the porous fiber layer due to external pressure. According to an embodiment, by having conductive yarn in flexible clothing or textile material, pressure can be sensed by effectively responding to deformation due to external pressure.