The invention discloses a pressure sensor using a fiber Bragg grating, and relates to a pressure sensor. The pressure sensor is provided with a sensor protective shell, a copper hollow elbow, a pipeline interface, a copper metal block, an upper metal protective sleeve, a lower metal protective sleeve, a fiber Bragg grating and an optical fiber protective sleeve, wherein the sensor protective shellis arranged on the peripheries of the copper hollow elbow, the pipeline interface, the copper metal block, the upper metal protective sleeve, the lower metal protective sleeve and the fiber Bragg grating; the copper hollow elbow is connected with the pipeline interface; the upper metal protective sleeve and the lower metal protective sleeve are connected with a tail end of the copper hollow elbowand the copper metal block respectively; the fiber Bragg grating is connected with an upper port of the copper hollow elbow and one end of the copper metal block respectively; and the optical fiber protective sleeve is arranged on the top of the sensor protective shell. Through the non-sticking scheme, the linear change of the central wavelength of the grating in a strain process can be better ensured in order to obtain more accurate measurement values.