A pressure detecting apparatus made by 3D printing technologies being able to be used in dangerous areas is provided. It mainly comprises a light source, a processor, a coupler, and at least one pressure transducer. The pressure transducer comprises a main body and a fiber grating. The fiber grating comprises a fiber Bragg grating sensor, and the fiber grating is fixed on the main body and covers the fiber Bragg grating sensor. When the main body is placed in a fluid area, the fluid would flow through the opening to deform the strain layer and generate a strain variation on the fiber Bragg grating sensor to cause a signal variation in the reflection frequency spectrum. The coupler is configured to couple to the light source and the pressure transducer to decode the signal variation into pressure parameters.